NFL players can disappoint from one year to the next for all kinds of reasons.

Injuries can take an extraordinary player and make him all too ordinary. That's what happened to DeSean Jackson in his first season with the Tampa Bay Buccaneers. The speedy receiver was also impacted by chemistry issues with quarterback Jameis Winston, who struggled to get him the ball on deep passes when he was on the field.

New teams and schemes can upset a player's equilibrium, and this is another primary reason for disappointing seasons. The Seattle Seahawks never quite figured out how to use Jimmy Graham over a three-year period, and the formerly prolific New Orleans Saints tight end was relatively muted in a more conservative passing scheme.

Players can also regress in concepts that do not suit their talents. The Oakland Raiders had a prominent quarterback in Derek Carr and two good receivers in Amari Cooper and Michael Crabtree last season, but a regressive and simplistic passing game led by former offensive coordinator Todd Downing just didn't work out.

There will be similar disappointments in 2018—it's a sad inevitability—and here's one player for each team we're pegging to fall below projected production.

Arizona Cardinals: QB Sam Bradford

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Talent has never been Sam Bradford's problem—when he has a good supporting cast around him, he shows the potential to be a top-10 quarterback. Ask the Saints, whose defense was eviscerated by Bradford and the Minnesota Vikings in Week 1 of the 2017 season. Bradford completed 27 of 32 passes for 346 yards and three touchdowns, making pinpoint throws all over the field. This after a 2016 season in which Bradford set a single-season record for completion percentage (71.6) that was broken by Drew Brees last year.

Sadly, it didn't last in 2017. Bradford sat out the next three games with knee issues, completed five of 11 passes against the Chicago Bears in Week 5, and his season was over. That was the latest chapter of a career in which Bradford has been bitten far too often by the injury bug—he's only played 16 games in a season twice (2010 and 2012), and he missed the 2014 season with a torn ACL.

The Arizona Cardinals signed Bradford to a two-year, $40 million contract with $15 million guaranteed to try to fix their quarterback situation, and if Bradford can stay healthy, he has as good a chance as anyone in the league to make that happen. But it's just as likely Bradford will have an injury that limits or eliminates his reps, and the Cards will have to put rookie Josh Rosen on the field in his place.

Atlanta Falcons: QB Matt Ryan

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In 2016, Matt Ryan was one of the best quarterbacks in the league, and he was offensive coordinator Kyle Shanahan's primary instrument. Shanahan created a passing game in which Ryan showed mobility like never before, and the veteran could throw to any number of receivers schemed open on a consistent basis. Ryan completed 69.9 percent of his passes, had a 38-to-7 touchdown-to-interception ratio in the regular season, and he threw nine touchdowns with zero interceptions in the postseason—a fact that was obviously eclipsed by the Atlanta Falcons' historic meltdown in Super Bowl LI.

When Shanahan was named the head coach of the San Francisco 49ers, the Falcons replaced him with Steve Sarkisian, and things did not go well. Ryan's productivity plummeted across the board as Sarkisian's less creative passing concepts gave Ryan far less wiggle room than Shanahan's had. Ryan's completion rate dropped to 64.7, his touchdown percentage fell from 7.1 to 3.8, and his adjusted net yards per attempt sank from 9.0 to 6.9.

Sarkisian has said all the right things about adjusting and improving in his second year with the team.

"Now I can make some of the tweaks that I feel like are needed for this offense to continue to grow," he told Matthew Tabeek of the team's official site. "I've got a really good understanding of every player—and the things that they're really good at, the things that they maybe need to work on and things that I would be wrong in putting them in position to do."

That's all well and good, but Shanahan in his second season with the Falcons presented Ryan with the tools to have an outlier campaign. Sarkisian hasn't shown the same level of schematic understanding, and unless he improves his playbook, it's tough to imagine Ryan will do much better than he did last season.

Baltimore Ravens: QB Joe Flacco

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In March, 2016, the Baltimore Ravens signed Joe Flacco to a contract extension that guaranteed him $62 million for injury and put themselves in a serious salary cap obligation to their star quarterback. That would've been fine if Flacco were performing as a top-tier starter, but between injuries, mechanical regression and a relative lack of offensive playmakers, Flacco hasn't come close to living up to that deal.

In fact, over the last three seasons, no quarterback with at least 1,000 passing attempts has been less efficient than Flacco. No matter how you slice his numbers, whether traditional or sabermetric, this three-year period has not been a good one for Flacco or the Ravens, who have missed the playoffs in all three of those seasons—their longest postseason drought since the first four years of the team's history.

Problem is, the Ravens can't do much about Flacco—they're stuck with him as a result of that contract. That's why the Ravens selected Louisville quarterback Lamar Jackson with the final pick in the first round of the 2018 draft and why the coaching staff is making noise about getting Flacco and Jackson on the field at the same time—it's trying to make the best of an untenable situation in which the franchise quarterback is on a major downhill slide. Unless Flacco reaches a point of excellence we haven't seen of him in years, there's no way he won't be a disappointment.

Buffalo Bills: QB AJ McCarron

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For the first four years of his career, AJ McCarron was one of the most talked about backup quarterbacks in the NFL, but he was never going to usurp Andy Dalton as the Cincinnati Bengals' starter. That didn't stop from taking shape some radical ideas about his value versus his performance—like when Cleveland Browns head coach and former Bengals offensive coordinator Hue Jackson wanted to give up second- and third-round picks for McCarron in October, but the Browns didn't get the paperwork done in time.

McCarron won a grievance that gave him the right to sign wherever he wanted, and he chose the Buffalo Bills. McCarron was decent in short duty with the Bengals, but he had few spectacular moments.

The problem is first-round pick Josh Allen would have to take giant leaps forward in his ability to read the field and process defenses before he's ready to hit the field, and the only other option the Bills have is second-year man Nathan Peterman, who threw five picks in a single half against the Los Angeles Chargers last season.

Now, word is that Peterman and Allen are outperforming McCarron in minicamps—Joe Buscaglia of WKBW had that observation. If Peterman winds up as the starter, that will be an indictment regarding McCarron's potential—and based on what we've seen of McCarron to date, there isn't much upside to talk about anyway.

Carolina Panthers: RB Christian McCaffrey

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From 2008 through 2017, just 20 running backs were selected in the first round of the draft. That's representative of the fungible nature of the position, which put pressure on the teams making those picks—if you're going to take a back in the first round, he'd better be special.

The Carolina Panthers selected Christian McCaffrey with the eighth overall pick last year, and based on what McCaffrey did in college, the pick wasn't too far out of hand. He was a highly valuable do-it-all player who excelled running outside and catching passes out of a full route tree. He was also an excellent return man.

Sadly, Carolina offensive coordinator Mike Shula struggled to put McCaffrey in any kind of position to succeed. Instead of the frequent intermediate and long passes the player took advantage of in college, McCaffrey ran a bunch of inside stuff that required more power than he has. And the routes he ran for the most part were far simpler and less inclined to be explosive. As a result, McCaffrey gained just 435 yards and scored two touchdowns on 117 carries, and though he caught 80 passes, he gained just 651 yards and scored five touchdowns. For a guy who piled up 2,664 yards from scrimmage for Stanford in 2015 and 1,913 more in 2016, his rookie campaign was quite a disappointment.

The Panthers have a new offensive coordinator in Norv Turner, but per ESPN.com's David Newton, head coach Ron Rivera pointed to McCaffrey's ability to run between the tackles. It's not McCaffrey's primary talent, and it never has been, and an increased portion of the wrong approach won't do anything positive for McCaffrey's future.

Chicago Bears: WR Allen Robinson II

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The Chicago Bears did a lot in the offseason to redraw an offense that could be charitably described as anemic in 2017. New head coach Matt Nagy is one of the NFL's more creative offensive minds. The additions of former Falcons speed receiver Taylor Gabriel and ex-Philadelphia Eagles tight end Trey Burton should help matters for second-year quarterback Mitchell Trubisky, but the marquee signing for the Bears this offseason was unquestionably former Jacksonville Jaguars receiver Allen Robinson II.

Robinson looked like one of the NFL's best young receivers in 2015, his second NFL season, when he caught 80 passes for 1,400 yards and tied for a league-leading 14 touchdowns. But despite his downfield speed and impressive route-running ability, Robinson managed just 73 catches for 883 yards and six touchdowns in 2016. And then, in the first game of the 2017 season, Robinson suffered a torn ACL and missed the rest of the season.

Robinson practiced for the first time since the injury during the Bears' May minicamp, but it's safe to say Chicago isn't sure what it has in Robinson. If he gets back to his 2015 numbers, that would be huge for the Bears' passing offense, but given his 2016 regression and the specter of the 2017 injury, that's a tough bet.

Cincinnati Bengals: QB Andy Dalton

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After a 2016 season in which he threw 18 touchdowns to eight interceptions and completed 64.7 percent of his passes, it was thought that Andy Dalton, after six NFL seasons, had reached his apex as a player. Never purely talented enough to make his way to the top of the quarterback stratosphere, Dalton's best bet was to reduce his mistakes, be as efficient as possible and let the players around him shoulder the load.

That didn't happen in 2017. Cincinnati's offensive line regressed, the run game wasn't much help at all, and the pressure Dalton faced made him less efficient. Yes, he threw 25 touchdown passes to 12 interceptions, but he completed 59.9 percent of his passes—the first time he completed fewer than 60 percent since his rookie year of 2011. Dalton isn't Aaron Rodgers or Tom Brady—he's not going to light up the NFL with one good receiver in A.J. Green.

Dalton has said he's excited to learn more about the schemes second-year offensive coordinator Bill Lazor has in store for him, and per Geoff Hobson of the team's official site, it sounds as if Hobson is going to streamline things so Dalton and his teammates can pick things up more easily.

The problem with this philosophy is that, if you're simplifying things for your quarterback, your quarterback will have to make up for that with his own ability to execute. Dalton isn't a bad quarterback, but he's going to need help from his coaches to find defined, consistent openings to make up for his own field-reading and mechanical issues.

Cleveland Browns: RB Duke Johnson Jr.

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Last season, Duke Johnson Jr. ran for just 348 yards on 82 carries, scoring four touchdowns. But he caught 74 passes for 693 yards and three touchdowns, posting receptions from the backfield and from the slot. In the offseason, the Browns signed former San Francisco 49ers back Carlos Hyde to be the primary power back and selected Nick Chubb in the second round. Chubb's college tape shows a player more similar to Hyde than Johnson.

So, where does Johnson fit? The Browns also traded for Miami Dolphins receiver Jarvis Landry, who will likely take some of Johnson's slot targets away. Landry hasn't been a dynamic outside receiver throughout his career, though he has that potential. In September, after a loss to the Pittsburgh Steelers in which Johnson, per ESPN.com's Pat McManamon, had 47 snaps all as a pass-catcher, head coach Hue Jackson said Johnson's role would change throughout the season. Which it did to a point, but one has to wonder how things will go with the Browns' new additions.

It's not that Johnson isn't a good player—he is an underutilized back and an effective receiver. But he may get edged out of his own position group.

Dallas Cowboys: QB Dak Prescott

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In the first two months of his second NFL season, Dak Prescott threw 14 touchdown passes to just four interceptions, and he took only nine sacks to go with 226 passing attempts. In the last two months of 2017, Prescott threw eight touchdown passes to nine interceptions and took 23 sacks to go with 264 passing attempts. Running back Ezekiel Elliott's six-game suspension and injuries to left tackle Tyron Smith were primary factors in Prescott's second-half downturn, as was his continued inability to find consistent chemistry with receiver Dez Bryant.

In 2018, Prescott will have Elliott and Smith, but the receiver situation is a bit unnerving. Bryant was released in April, and to cushion that blow, Dallas signed ex-Jacksonville receiver Allen Hurns and selected Colorado State product Michael Gallup in the third round. Those are good moves—both Hurns and Gallup have a lot of potential as possession receivers—but outside the inconsistent Terrance Williams, there isn't a lot of explosiveness in the receiver corps, and tight end Jason Witten's retirement took a consistent receiver out of Prescott's orbit.

Ostensibly, the Cowboys will have a run-based system that features a lot of play-action—that's been the idea since Elliott became the fulcrum of the offense. But any time without him, and any serious injury dings to the offensive line, could affect Prescott just as negatively as it did in 2017.

Denver Broncos: QB Case Keenum

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Case Keenum was the Vikings' secret weapon in 2017, helping the team to the NFC Championship Game after quarterback Sam Bradford was injured. In Pat Shurmur's offense and with Stefon Diggs and Adam Thielen as his primary receivers, Keenum had by far his best NFL season, completing 67.6 percent of his passes for 3,547 yards and 22 touchdowns with seven interceptions.

The playoffs showed a bit of regression—especially against the Eagles' outstanding defense—but Keenum appeared to have turned several corners. His quickness to throw the ball was accentuated by a surprisingly deft touch with the deep ball, and it wasn't a huge surprise when the quarterback-deprived Denver Broncos signed him to a two-year, $36 million deal with $25 million guaranteed.

But if the Broncos want the Keenum they saw in the Twin Cities, they'll have to present him with a similarly expansive passing offense and receivers who can get open with both physicality and speed. Keenum will have such players in Demaryius Thomas and Emmanuel Sanders, but Bill Musgrave's unit—which was the offense in place for Denver's three-man quarterback disaster in 2017—doesn't project to be as much of a test for enemy defenses as Shurmur's was.

It's clear that Keenum needs playmakers and a scheme optimized for his success. There's nothing wrong with that, but if any of those factors aren't present, problems—and disappointments—will arise.

Detroit Lions: RB LeGarrette Blount

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It seems a long time ago that LeGarrette Blount scored 18 rushing touchdowns for the New England Patriots, but that happened in the 2016 season. The veteran won his second straight Super Bowl with the Philadelphia Eagles last season, gaining 766 yards on 173 carries as part of a running back committee in a forward-thinking offense.

The Detroit Lions backfield has been a disaster for a while now, and Blount—whom head coach Matt Patricia knows from their Patriots days—should add a bit of dynamism in the red zone.

But as an every-down back, Blount falls short at this point in his career, and it's entirely possible that Auburn product Kerryon Johnson, selected in the second round of the 2018 draft, could take reps from Blount in a goal-line role. Per Pro Football Focus, Johnson ran between the tackles for 54 percent of his yards in college, and he scored 18 rushing touchdowns in 2017.

Green Bay Packers: WR Randall Cobb

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Randall Cobb has struggled over the last few seasons to amass numbers in line with his four-year, $40 million contract. He caught 66 passes for 653 yards and four touchdowns in 2017, and in the final year of the deal, the Green Bay Packers have a right to expect more.

It's not all his fault, though. At his peak, Cobb was a premier slot/outside receiver who gained advantages through his speed and agility when he was schemed open. As head coach Mike McCarthy's passing game became more staid and based on matchups, Cobb lost that advantage. He's not a particularly physical receiver, and he's not equipped to win contested catch battles.

It's possible Cobb would benefit from a move to a team more interested in crossing routes and flood concepts, which would help him get open. In the meantime, he'll struggle in the system he's in.

Houston Texans: DL J.J. Watt

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Watt won the AP Defensive Player of the Year award in 2012, 2014 and 2015, and during that era, he was not only the best defensive player in football but also quite possibly the most destructive interior pass-rushing defensive lineman in league history. No matter where he lined up, he was unblockable and unstoppable.

Apparently, the only thing that could slow Watt down was his own body. After starting every game in the first five years of his NFL career, Watt has played just eight games over the last two seasons, and he has only 1.5 sacks to show for it.

There is good news, however, as NFL Network's Ian Rapoport reported Watt probably won't start the 2018 season on the physically unable to perform list. Head coach Bill O'Brien told Good Morning Football he expects Watt to be at full strength.

If he is able to get on the field for a full season again, the next question is whether Watt, 29, can be the player he once was. Most pass-rushers aren't as effective after age 30, and given his recent injury history, Watt's potential return to greatness should be viewed with some skepticism.

Indianapolis Colts: QB Andrew Luck

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Of all the marquee players in the NFL, Andrew Luck has injuries to thank as much as anyone for the recent divide between his performance and potential—and his future is no sure thing. Luck played the 2016 season with a shoulder injury, missed the 2017 season because of that and, with on the verge of summer, threw a high school-size football.

Luck told Albert Breer of The MMQB that his shoulder pain is gone, but the limitations on his throwing have to cause concern.

If Luck starts the season at full health and can make all the throws he could before, the Indianapolis Colts could once again have the guy who led the league in touchdown passes in 2014. Luck threw 31 touchdown passes in 2016 despite his injury, so there's reason to believe we might see the player we saw before. But for those hoping for a smooth recovery, there's been a lot of speed bumps.

Jacksonville Jaguars: QB Blake Bortles

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If the Jacksonville Jaguars had stuck to their first-half script of run-pass options that were confusing the Patriots in the AFC Championship Game, they might well have played their first Super Bowl in franchise history. A 14-3 second-quarter lead turned into a 24-20 loss in part because when the Jaguars' passing schemes were simplified, Bortles was unable to take advantage. Not that Bortles played badly—he completed 23 of 36 passes for 293 yards and a touchdown—but the team's inability to score a touchdown in the second half was the decider.

General manager David Caldwell said at the scouting combine that Bortles' new deal was a reflection of the team's faith in Bortles over the long term and that the Jags aren't looking at Bortles as a placeholder.

But if the 2018 version of Bortles shows the same mental and mechanical inconsistencies that have been evident throughout his career, Caldwell and his coaching staff would have to weigh moving on. Moreover, if Bortles can't hit the proverbial next level, that'll be one more season in which the team's stacked roster will have been upended by inconsistency at the game's most important position.

Kansas City Chiefs: WR Sammy Watkins

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Throughout his career, new Kansas City Chiefs receiver Sammy Watkins has mixed potential with inconsistent route-running. He was supposed to be a fulcrum of Sean McVay's offense in Los Angeles last season, but he never quite found a chemistry with Jared Goff and caught just 39 passes in 70 targets for 593 yards and eight touchdowns.

Watkins' ability to beat cornerbacks with speed and strength in contested catch situations was never in question—that's why he was effective in the red zone, at least—but he hasn't been a reliable receiver since 2015, when he totaled 1,047 receiving yards and had a catch rate above 60 percent for the only time in his career.

Per BJ Kissel of the team's official site, Watkins is developing a rapport with first-year starting quarterback Patrick Mahomes, and that's obviously good for the Chiefs. But head coach Andy Reid expects a lot out of his receivers when it comes to aligning with the complexities of the West Coast offense. Reid has always added vertical elements to make his offenses more explosive, and Watkins is reportedly putting in extra time to pick up the offense, but we'll see whether that shows on the field.

Los Angeles Chargers: LB Jatavis Brown

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There are times when a player's regression is less his own fault and more the responsibility of a coaching staff that doesn't seem to know how best to use him. In 2016, Jatavis Brown proved to be one of the most dynamic and versatile rookie defenders in the league, amassing 63 solo tackles, 3.5 sacks, two forced fumbles and looking great in coverage.

But the switch in 2017 from John Pagano to Gus Bradley as defensive coordinator had a clear and detrimental effect on Brown's production and effectiveness. He had zero sacks, nine fewer solo tackles and appeared to have fewer opportunities to do much of anything. Brown is an athletic and savvy player—an undersized linebacker who excels in sub-packages. Yet, for all of Bradley's defensive acumen, he couldn't figure out how Brown fit.

That problem might not be over. Per ESPN.com's Eric D. Williams, Brown is a potential starter based on his adherence to Bradley's scheme and a program to gain weight. And if Brown adds to his 230-pound frame, making him a more traditional run-stopping linebacker, that may take away from some of his athleticism and make him more of a "box" player. That would be unfortunate typecasting, given Brown's effectiveness in Pagano's system and his overall athletic potential.

Los Angeles Rams: CB Marcus Peters

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There's no question Marcus Peters has become one of the NFL's most effective turnover machines. Through his three NFL seasons, no other defender has more than his 19 interceptions, and the man in second place, Reggie Nelson, is five behind. Peters is aggressive and athletic enough to deal with any receiver at any time, and at his best, he can erase the league's best receivers throughout a game.

The Rams acquired Peters from the Chiefs for a 2018 pick swap and a 2019 second-round pick. Though Peters is a perfect fit in Wade Phillips' defense, you may wonder why Kansas City was OK with trading such a valuable player on a rookie contract for seemingly low draft capital.

As opportunistic as he can be, Peters runs hot and cold. In Week 13 against the New York Jets last season, Peters took an official's flag, threw it into the stands and left the game early. He was suspended for a game by the team. And he's also allowed 15 touchdowns through his first three seasons, per Pro Football Focus.

Peters makes plays on throws far away from his area because he is so athletic, but he can also be taken out of his own space too often. If the Rams can't curb his negative traits, Peters' interception totals won't make up for them.

Miami Dolphins: OG Josh Sitton

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The Dolphins have struggled to put a credible offensive line together over the last few seasons, and cutting center Mike Pouncey didn't help. One thing that may assist Miami's interior line was the decision to sign Josh Sitton.

At his best, both with the Packers and Bears, Sitton has been one of the best guards in the league. He's tremendously athletic and mobile, and though he doesn't have elite strength at the line of scrimmage, his adherence to proper technique allows him to protect his quarterback even when he's getting bent back by a more powerful player.

At this point in his career, though, Sitton's injury history is worrisome. The Bears declined his option in part because he's missed multiple games in each of the last two seasons, and playing through injuries, he didn't always look his best. Sitton still has a fairly high ceiling when healthy, but at age 32, he may struggle to stay on the field all the time in 2018.

Minnesota Vikings: QB Kirk Cousins

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When the Vikings signed Kirk Cousins to a three-year, $84 million contract with all $84 million guaranteed, they didn't just alter the financial landscape of the NFL—they also went all-in on a quarterback whose tape shows glaring inconsistencies that may not be fixable.

Cousins has been prolific, to be sure—he's thrown for more than 4,000 yards in each of the last three seasons, and the 2012 fourth-round pick from Michigan State has worked hard to correct mechanical flaws that bedeviled him early in his career and led to stretches of unpredictable play.

When I did an extensive tape study of Cousins' play, I saw a quarterback who had receivers schemed open for him, but he often failed to take advantage of his own playbook in crucial situations because he struggled to read coverages and react in time to defensive movement.

That was an especially problematic issue in the red zone, where Cousins' passer rating dropped from 93.9 overall last season to 80.7. Inside opponents' 10-yard lines, that rating plummeted to 67.5. Cousins is at his best in the middle of the field, where receivers have more time to run their routes and there are more openings because there's more space.

New Vikings offensive coordinator John DeFilippo has talked about creating more favorable matchups in the red zone for his quarterback, but if Cousins isn't better able to take advantage of them (Washington Redskins head coach Jay Gruden did a nice job creating matchup advantages), he will continue to be what he has been: a statistically prominent quarterback who has issues when matchups are tougher.

New England Patriots: TE Rob Gronkowski

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Rob Gronkowski talked about possibly retiring, and given his injury history, that's not all too surprising. He's committed to the 2018 season, but have the Patriots remained committed to him? Per Pro Football Talk's Mike Florio, the team was making offers for their tight end just a few days before the draft. Gronk is a generationally great player who hasn't played a full season since 2011, his second in the NFL.

He did play 14 regular-season games last year, catching 69 passes on 105 targets for 1,084 yards and eight touchdowns, and he was certainly New England's most effective player in the Patriots' loss to the Eagles in Super Bowl LII, catching nine passes for 116 yards and two second-half touchdowns.

That said, between his injury history, the potential end of his career and the Patriots' possible interest in moving on without him, one wonders if we'll ever see the best of Gronkowski again. When he's been on and healthy, he's quite possibly the best receiving tight end in NFL history, but there are a lot of complications ahead of this season.

New Orleans Saints: LB A.J. Klein

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The Saints signed A.J. Klein to build on his history as a backup linebacker for Luke Kuechly. Klein didn't have Kuechly's athleticism or supernatural field-reading abilities, and he couldn't match Kuechly's pass-coverage abilities, but he was a decent enough run-stopper to seemingly make this deal reasonable.

But Klein was one of the seasonlong disappointments in a defense that improved drastically from the start of the year. Not only did he continue to struggle in coverage, but he also had problems getting to outside runners when he was placed closer to the line of scrimmage. And against receivers in the flat and up the seam, he looked out of place far more than he should have.

How he'll fit into the New Orleans defense in 2018 remains a mystery, but of all the players on this list, Klein may need the most improvement in performance if he's to avoid disappointment status.

New York Giants: QB Eli Manning

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If Eli Manning has a subpar season in 2018, it certainly won't be for lack of effort from the Giants front office.

In 2017, Manning struggled with a static, unexciting passing game and mercurial head coach Ben McAdoo, who benched Manning for the team's Week 13 game against the Raiders—a move that led to McAdoo's firing. But new general manager Dave Gettleman signed left tackle Nate Solder and running back Jonathan Stewart, selected Penn State running back Saquon Barkley in the draft and tried to maintain a positive relationship with receiver Odell Beckham Jr. despite a contract dispute.

The addition of new head coach Pat Shurmur will certainly give Manning an uptick in the playbook department, and Barkley will add tons of explosiveness and versatility in both the running and passing games—but Manning is still in the twilight of his career. His deep ball has been declining over the past few years, his intermediate accuracy isn't what it used to be, and Solder is unlikely to protect Manning's blind side to the point where he'll be able to avoid the fact that he's not an exceptional quarterback under pressure anymore.

Manning's older brother Peyton managed to go out on top, winning a Super Bowl with the Denver Broncos even as his skills had declined radically because the team around him was so strong. Eli would obviously love to have that same end to his career, but despite Gettleman's efforts, the Giants aren't quite in that class—and they need their quarterback to pick up the slack.

New York Jets: WR Robby Anderson

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Last season proved to be a breakout campaign for Robby Anderson, an undrafted Temple product. In his second year and in an offense that was expected by some to be the league's worst, Anderson surprised most observers by catching 63 passes for 941 yards and seven touchdowns. He has shown the deep speed to get past multiple coverages, and his route running has improved.

The problem may be more off the field. Anderson has experienced multiple issues with law enforcement over the last year, and he received six months of probation as the result of a reckless driving charge.

Anderson has said he's turned his life around, and one certainly hopes that's the case. It's unclear as to whether he'll face any league discipline, but the Jets need him to continue to develop as a receiver on the field and stay out of trouble off it.

Oakland Raiders: WR Jordy Nelson

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Both Amari Cooper and Michael Crabtree were relative disappointments in the Oakland Raiders' passing game last year, as was quarterback Derek Carr. It seemed everyone in that offense had trouble aligning with former offensive coordinator Todd Downing's simple route concepts.

New head coach Jon Gruden, who'll run Oakland's offense his way, should help a bit. However, it's been several years since Gruden did more than provide color on Monday Night Football and talk to quarterback prospects in his Gruden's QB Camp series.

The Raiders signed former Packers receiver Jordy Nelson to a two-year, $15 million contract in March. Ostensibly, Nelson will take the place of Crabtree, who was released in March to free salary-cap space. That's a good theory if the Raiders are getting the Nelson who aligned with Aaron Rodgers in the recent Green Bay glory years—not only was Nelson an amazing route-runner both outside and in the slot, but he also fooled defenses with loping speed up the seam and down the sideline.

But based on his tape over the last couple of years, he might be little more than a possession receiver. Though he played in 15 games last season, Nelson caught just 53 passes for 482 yards and six touchdowns, which was a major step down from previous seasons.

Nelson doesn't show the same game-breaking speed he once had, and though Gruden and offensive coordinator Greg Olson should be more creative than Green Bay head coach Mike McCarthy was with his route concepts, Nelson may need more schematic help than in previous years.

Philadelphia Eagles: CB Jalen Mills

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It's hard to find a weakness in the Philadelphia Eagles defense—of course, that's one reason they're the defending Super Bowl champions. But if there's a cause for concern, it's third-year cornerback Jalen Mills. The LSU alum improved on a highly disappointing rookie season with three interceptions in 2017, but he still looked out of place in coverage far too often.

It's possible Mills' development will continue—he's athletic enough to get the job done. But with questions surrounding the health of second-year corner Sidney Jones, who missed his rookie season with a torn Achilles tendon and missed the team's minicamps with what was called a lower-body injury, it will be up to Mills to lock down an outside spot.

The early word has been good regarding Mills' preseason performances, but things get tougher when you're in the limelight, and while Mills has shown improvement, he'll need to do more if he's to help the Eagles defend their title.

Pittsburgh Steelers: S Morgan Burnett

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The Pittsburgh Steelers secondary was a disappointment in 2017 at both the cornerback and safety positions, and that's a major problem for a defense that put six defensive backs on the field 24 percent of the time, per Football Outsiders. When a team's base-defense guys aren't doing their jobs and its situational reserves are pressed into service, things can get messy.

So, the Steelers went all out at the safety position in the offseason, signing Morgan Burnett, 29, after releasing Robert Golden and Mike Mitchell and selecting Virginia Tech hybrid defender Terrell Edmunds in the first round. Edmunds is an incredible athlete who can do everything from dime linebacker to deep safety, but Burnett's abilities may be more limited at this point in his career.

The ninth-year veteran was a highly versatile player in his prime but became more of a linebacker-depth, run-stopping safety over the last few seasons with the Green Bay Packers. That's an important skill in Pittsburgh's defense, especially since the team is trying to find the best way to replace hyper-athletic linebacker Ryan Shazier. But if fans are expecting Burnett to perform multiple tasks in a hybrid defense, they may be in for a surprise.

San Francisco 49ers: QB Jimmy Garoppolo

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In six games (five starts) as the San Francisco 49ers quarterback following his trade from the Patriots, Jimmy Garoppolo looked like the team's first legitimate signal-caller since it kicked Colin Kaepernick to the curb.

He completed 67.4 percent of his passes for 1,560 yards, seven touchdowns and five interceptions, leading general manager John Lynch and head coach Kyle Shanahan to pull the trigger on a five-year, $137.5 million contract that gives the 49ers a $37 million salary-cap obligation in 2018 and made Tom Brady's former backup the third-highest-paid quarterback on a per-year basis.

Had the 49ers gone with a more modest contract, Garoppolo's potential and production might have been more in scale. But with this deal, he has the pressure to be the league's best at his position, and while he showed ability in Shanahan's multitiered passing game, he has issues to address.

When watching Garoppolo's five picks on tape, one sees a combination of receiver drops and bad quarterback decisions. Though he's learned a lot about the position, he is also prone to throwing into coverages that have already converged, and that's a problem he'll need to fix quickly if he's going to live up to what his contract says about his responsibilities.

That's not to say the 49ers made a mistake or that Garoppolo is a bad player. But the team made a deal based on the signal-caller they want as opposed to the quarterback he is at this point in his career.

Seattle Seahawks: OL Germain Ifedi

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The hope among Seattle Seahawks fans is that new offensive line coach Mike Solari will improve his front five in ways Tom Cable never could.

His most prominent challenge will be to remake right tackle Germain Ifedi into a consistent blocker, despite the fact that in two seasons at both tackle and guard, the 2016 first-rounder has shown little more than massive technical issues and a temperament that has him racking up far too many penalties.

Solari has been more of a power-blocking advocate, while Cable installed a basic (and easy to beat) version of inside and outside zone. The power/counter/trap scheme would seem to fit Ifedi's stature, as he's best in a phone booth and a liability on the move.

"He has all the tools—big, athletic guy, you know, great length—so just trusting things and having good technique, I think he's going to be great," Seattle left tackle Duane Brown recently said of Ifedi, per Corbin Smith of Seahawks Wire.

But before Ifedi is able to compete in any blocking scheme, he'll have to finish major work on technique flaws that have him playing off-balance and losing power most of the time. Development has been slow to come, and a new coach can only do so much.

Tampa Bay Buccaneers: WR DeSean Jackson

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When the Bucs signed DeSean Jackson to a three-year, $33.5 million contract with $20 million guaranteed in March 2017, they thought Jackson would take the top off every defense with his vertical speed as he had with the Eagles and Redskins.

Based on my own tape study, I was sure that Jackson was the difference-maker Tampa Bay needed to put its passing offense over the top. It was an easy conclusion, as Jackson (4.35 40-yard dash) has been one of the best speed receivers of his era. He had been far more than a straight-line guy. He had also learned how to beat the best cornerbacks and safeties in the league with his impressive route understanding.

However, Jackson's first season with the Bucs was a washout for a couple of reasons: Injuries cost him two games and his speed, and he seemed to lack chemistry with quarterback Jameis Winston.

Per ESPN.com's Jenna Laine, Winston and Jackson have been working together this offseason, but if the wide receiver isn't able to improve his numbers over last season's 50-catch, 668-yard, three-touchdown totals, he'll go into the final year of his contract as more of a financial liability than an on-field asset.

Tennessee Titans: CB Logan Ryan

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Many teams have made the mistake of overpaying former New England Patriots when the players become free agents, thinking they will be as effective in their schemes as they were in coach Bill Belichick's. Generally, it doesn't work that way, and Titans cornerback Logan Ryan is one of the most prominent current examples.

Signed to a three-year, $30 million contract with $16 million guaranteed in March 2017, Ryan struggled through injuries in his first year in Tennessee as well as his slight change in responsibility.

With the Patriots, Ryan was best as a slot corner who could occasionally kick outside. As more of an outside man in 2017, however, he ran into trouble. Because of his size (5'11", 195 lbs) and occasional lapses in route recognition, he was more susceptible to coverage breakdowns. Ryan failed to record an interception for the first time of his NFL career, and his coverage was not up to his New England standards.

If Ryan is able to come back healthy and have more of an inside role in 2018, he could show an upswing in performance. But a return to his 2017 responsibilities could lead to more disappointment.

Washington Redskins: TE Jordan Reed

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There's a saying in the NFL that health is a skill, and there's a lot of truth to that. No matter how talented a player may be, if he can't get on the field for physical reasons, his team will have to decide how to replace his impact.

This may be the scenario for Washington Redskins tight end Jordan Reed. An exceptional pass-catcher along the formation and split wide when healthy, Reed hasn't been near 100 percent as often as the team would like. He's never played all 16 games in a season, and he missed 10 games in the 2017 campaign with shoulder, hamstring, chest and toe injuries.

Reed needed toe surgery this offseason, and though he looked good in OTA drills, per ESPN's John Keim, it would be a leap of faith to think that he'll be the same player he's been at his best—which, sadly, he hasn't been often throughout his five-year career.