With training camps kicking off across the league, NFL Nation reporters pick a hidden storyline to watch for every team.

AFC East | AFC North | AFC South | AFC West

NFC East | NFC North | NFC South | NFC West

AFC EAST

Last offseason, the Bills made Jerome Felton the league's highest-paid fullback, but he played in only 26.5 percent of offensive snaps, seventh-most among the shrinking group of NFL fullbacks. The Bills signed Glenn Gronkowski, the youngest brother of Rob Gronkowski, as an undrafted free-agent this spring, and general manager Doug Whaley stated "Goose" Gronkowski has a "good shot" to make the 53-man roster. That would put Felton and his $2.3 million cap number at risk, especially considering that the Bills will need to find 2017 salary-cap space to re-sign top cornerback Stephon Gilmore and quarterback Tyrod Taylor. -- Mike Rodak

The Dolphins plan to use a lot of "wide-nine" alignments on their defensive line to boost their pass rush -- they ranked tied for 25th in sacks last season (31.0) -- and set the perimeter. The alignment spreads out defensive tackles and defensive ends, but the weakness is it leaves more open space in the middle. Whether smallish linebacker Kiko Alonso can successfully take on and shed offensive linemen, an area in which he struggled last year with the Eagles, will be something to watch. -- James Walker

Do the Patriots have enough at running back? They didn't select a running back in the draft, and while they might have their best pass-catching stable of backs in 2016, there is still a question of who leads the way as a physical, punishing presence. LeGarrette Blount, whose 2015 season ended in December with a hip injury, didn't practice in the spring but is the leading candidate. -- Mike Reiss

No one is talking about the big question at cornerback: Who will start opposite Darrelle Revis? The Jets decided to stay in-house to replace Antonio Cromartie, but neither Buster Skrine (better in the slot) nor Marcus Williams (the No. 4 corner) are sure things. They can't operate an effective man-to-man defense if there's a leak at cornerback. -- Rich Cimini

AFC NORTH

There has been plenty of talk about the Ravens' changes in the secondary, but one position that often goes overlooked is nickel cornerback. Baltimore is looking to upgrade from Kyle Arrington, and the competition for that spot is among the more underrated position battles on the team. The Ravens signed veteran Jerraud Powers and drafted Tavon Young in the fourth round. Will Davis, who tore his ACL last season, can also work himself into the mix. Improving the pass defense is a priority after the Ravens allowed a franchise-worst 30 touchdown passes and intercepted an NFL-low six passes last season. -- Jamison Hensley

One of the more undervalued Bengals storylines this offseason revolved around the team's replacement of six assistant coaches. New defensive line coach Jacob Burney could be one to watch as he takes over a unit that features dominating defenders Geno Atkins and Carlos Dunlap, and is simultaneously trying to groom rookie Andrew Billings. Burney may not be well known to fans, but that probably won't be the case for long. This spring, Bengals linemen piled effusive praise upon him. Many called Burney a good teacher with an intense and stern disposition they need to make an already good position group even better. -- Coley Harvey

The Browns need a right tackle to replace Mitchell Schwartz, and Alvin Bailey appears in line to be the guy . Bailey, a restricted free agent, was not tendered an offer by Seattle after starting three games last season, so if he doesn't work out the position becomes a crapshoot. Austin Pasztor and rookie Shon Coleman could get a chance to takeover. -- Pat McManamon

Nose tackle used to be a position of pride for the Steelers, but now it's sort of an afterthought. Steelers coaches are quick to point out that they play a traditional nose tackle less than one-third of the time because of all the three-receiver sets from opposing offenses. But if the Steelers had a dominant player in that spot, the percentages would go up. They can't mask this position in camp. Someone has to emerge. Third-year nose tackle Dan McCullers has played sparingly in two seasons, and now the team is counting on him to start. McCullers hopes offseason surgery to correct a torn labrum will help him rediscover his nasty streak. The man can move a pile. At 6-foot-7, 352 pounds, he's massive. But can he master the position? -- Jeremy Fowler

AFC SOUTH

The relationship between linebackers Brian Cushing and Benardrick McKinney is worth watching. Cushing is the veteran and McKinney is in his second year. They're developing the kind of chemistry needed for success in the middle of the defense. Cushing said it feels a little bit like the relationship he had with former Texans linebacker DeMeco Ryans in the early years of his career. -- Tania Ganguli

Keep an eye on the nickel cornerback spot. Veteran Darius Butler has held that position all four years he has been with the Colts. But general manager Ryan Grigson has publicly said he expects second-year cornerback D'Joun Smith to push Butler. "D'Joun has got to step up this year," Grigson said earlier this year. "He's got to compete for the nickel spot." Butler has the edge at the moment because Smith missed the team's offseason workouts while dealing with a knee issue. -- Mike Wells

The Jaguars drafted strong safety Johnathan Cyprien in the second round in 2013, but he has just two interceptions and three forced fumbles, and now he's fighting with James Sample, the team's fourth-round pick in 2015, to remain the starter. Because the Jaguars in previous years didn't have a free safety capable of playing single-high coverage, Cyprien has had to work in coverage more than they wanted. With Tashaun Gipson now in Jacksonville, however, Cyprien can stay closer to the box, which is his strength. -- Mike DiRocco

During the Titans' miserable 2014 and 2015 seasons, the cornerbacks have too frequently lined up well off the receivers they are covering. At times it appeared they were so wary of getting beat over the top that they were willing to give up plays in front of them, even if that meant third downs were converted. New secondary coach Deshea Townsend and his assistant Steve Jackson both played as defensive backs and should help give the Titans secondary the confidence to play more aggressively. One of the newcomers to the group, cornerback Brice McCain, said he prefers to play tight on his man from the snap in order to control the route more. It's an attitude the Titans should hope is contagious. -- Paul Kuharsky

AFC WEST

Danny Trevathan, the Broncos' leading tackler in two of the past three seasons, is gone to Chicago, which means his inside linebacker job is open. Whomever takes his vacant spot could get 100 tackles this season. The Broncos' defensive scheme demands, and rewards, active linebackers, and it's Todd Davis and Corey Nelson who are battling for the position. Davis, once an undrafted rookie signed by the Saints, was claimed on waivers by the Broncos in 2014 while Nelson was a seventh-round draft pick by the Broncos in '14. The Broncos think enough of both to have not signed an inside linebacker in unrestricted free agency, and they didn't use a pick in his year's draft on the position. Davis has started games, and the Broncos like his quiet intensity and preparation. But Nelson has shown quality instincts and is a smart player. The battle is undecided as training camp opens. -- Jeff Legwold

The Chiefs are counting on continuity to improve their offensive line play. Because of injuries and poor play, they constantly shuffled personnel last season. They started nine different line combinations. Early in offseason practice this year, however, they settled on five starters, including free-agent acquisition Mitchell Schwartz at right tackle and fourth-round draft pick Parker Ehinger at left guard. Kansas City appears ready to stick with that group. -- Adam Teicher

Keep an eye on a battle at a position that gets little to no recognition but is one of the more important gigs in the game. Or have you already forgotten about the time Dennis Allen forgot to have a backup long-snapper at the ready? Jon Condo has already earned a Pro Bowl nod, but he missed the final three games with a shoulder injury last year and the Raiders added Andrew East to compete this offseason. -- Paul Gutierrez

The Chargers did not make many changes on an offensive line that performed poorly in 2015. But general manager Tom Telesco is betting on the addition of veteran offensive line coaches Jeff Davidson and Dave Deguglielmo to turn things around. Both have emphasized a back-to-fundamentals approach to improve a group that suffered a rash of injuries last season. -- Eric D. Williams

NFC EAST

The Cowboys promoted Joe Baker to secondary coach in the offseason and he has one task: create takeaways. Brandon Carr has not had an interception in 36 straight games. Orlando Scandrick has never had more than two in a season and is coming off a serious knee injury that kept him off the field in 2015. Morris Claiborne has one pick in his past 19 games. While an improved pass rush will help create takeaways, the corners have to find a way to make plays on their own. -- Todd Archer

The Giants this offseason signed three prominent free agents -- cornerback Janoris Jenkins, defensive tackle Damon Harrison and defensive end Olivier Vernon -- to turn around the league's worst defense. They drafted cornerback Eli Apple 10th overall. Does it really matter if they don't have a middle linebacker? The Giants need to find a leader in the middle of their defense. Jasper Brinkley, Keenan Robinson, Kelvin Sheppard and B.J. Goodson are in the running. None may be three-down options. The Giants desperately need one of the four to step into the role. -- Jordan Raanan

The under-the-radar storyline for the Eagles is the lack of proven offensive playmakers after Chip Kelly's unloading of DeSean Jackson, LeSean McCoy and Jeremy Maclin. Injury-prone Ryan Mathews is likely the starting running back. None of the wide receivers has ever had a 1,000-yard season. They have good tight ends, but Zach Ertz hasn't quite had his breakout season and Brent Celek is 31. New coach Doug Pederson has his work cut out for him. -- Phil Sheridan

The development of second-year slot receiver Jamison Crowder will be worth watching. Coaches were thrilled with what they saw in the spring, saying he was more elusive off the line and that he'll continue to be a key part of their three-receiver packages. If he and first-round pick Josh Doctson both develop well this season, the Redskins could save money by letting pending free agents DeSean Jackson and Pierre Garcon walk. -- John Keim

NFC NORTH

The interior of the Bears' offensive line is in flux. Three-time Pro Bowler Kyle Long is penciled in at right guard after the club signed veteran right tackle Bobby Massie in free agency, but left guard and center remains wide open. The Bears expect second-round pick Cody Whitehair to start at one of the spots, but which one is yet to be determined. Besides Whitehair, the Bears have three veterans with starting experience -- Ted Larsen, Hroniss Grasu and Amini Silatolu. The expectation is the Bears will not have their starting five finalized until around the third exhibition game against Kansas City. -- Jeff Dickerson

While a lot of attention has gone to Taylor Decker at left tackle and what the offense will do without wide receiver Calvin Johnson, what happens in the middle of the Lions' line is going to have a large impact on Detroit's 2016 success. Incumbent center Travis Swanson is fighting for his job, trying to hold off third-round pick Graham Glasgow and veteran Gabe Ikard. The Lions are giving Swanson every chance to win his job again in 2016, but his inconsistency last season caused some major problems. The Lions can't afford to have that again this season. -- Michael Rothstein

Aaron Rodgers surely knows the Packers' offense inside and out better than anyone. However, Rodgers always said that title belonged to John Kuhn. It's why Rodgers liked the security blanket of the veteran fullback, who could do everything from pass protect in blitz situations, block on short-yardage plays and even carry and catch the ball out of the backfield in critical situations. It's no wonder Rodgers sounded disappointed that general manager Ted Thompson decided not to bring back Kuhn for a 10th season. It may not seem like a big deal given how little teams use fullbacks, but it was important to Rodgers and now it's over. How will that impact the quarterback and the offense? -- Rob Demovsky

The Vikings made Harrison Smith the highest-paid safety in the league this spring, but the spot next to him has been in flux for several years, and there's no guarantee the Vikings have solved it. They signed former Titans safety Michael Griffin to a one-year deal this offseason, but Griffin will have to battle Andrew Sendejo, as well as young players such as Antone Exum and Anthony Harris, for a spot. Coach Mike Zimmer said in February that Smith can be an even more dynamic player if he has the right safety next to him. Time will tell, though, if the Vikings have a player who can be effective enough in coverage for Smith to move around Zimmer's defense more than he has in the past. -- Ben Goessling

NFC SOUTH

One thing to watch at Falcons' training camp is the battle for the No. 3 corner spot behind Desmond Trufant and Robert Alford. Jalen Collins is suspended for the first four games for violating the league's policy on performance-enhancing substances, meaning others have to get valuable reps ahead of Collins leading into the season opener. Akeem King, converted receiver C.J. Goodwin, and DeMarcus Van Dyke will battle it out for a significant role, considering the Falcons will play their share of nickel and have Alford covering the slot. Will the Falcons add a veteran corner to compete? They looked at Leon Hall and Brandon Boykin but signed neither. -- Vaughn McClure

The Panthers have been looking for a third tight end who can contribute as a receiver for the past few years as insurance in case something happens to Pro Bowler Greg Olsen. They appear to have three good candidates in Scott Simonson, Beau Sandland and Braxton Deaver. Sandland, a seventh-round pick-up, and Deaver, an undrafted free agent, stood out at times during the offseason. The third tight end didn't have a catch last season, and backup Ed Dickson had only 17 catches. For a team that uses a lot of two tight-end sets, finding another weapon is a quiet priority. -- David Newton

The Saints need to figure out some way to manufacture a pass rush if they're going to have any chance at improving one of the league's worst defenses. They didn't add any edge rushers opposite Cameron Jordan in free agency or the draft. Then they lost projected starter Hau'oli Kikaha to a summer knee injury. Several guys are in the mix to replace Kikaha at defensive end. But New Orleans will rely heavily on a push up the middle from new defensive tackles Sheldon Rankins and Nick Fairley, plus the creativity of defensive coordinator Dennis Allen, who's not afraid to blitz. -- Mike Triplett

Much has been made about the Bucs' secondary allowing a 70 percent completion percentage last year. That doesn't just fall on the guys on the backend, though. "Rush and cover" go hand-in-hand. The defense has not been able to get consistent pressure with a four-man rush, finishing 14th in the league with 38 sacks last year. The team is hoping that new additions Robert Ayers and Noah Spence, along with new defensive coordinator Mike Smith, can help. The Bucs haven't had double-digit sacks from a single player since Simeon Rice in 2005. -- Jenna Laine

NFC WEST

There has been a lot of focus on individuals (such as Tyrann Mathieu, Carson Palmer and Chandler Jones) or position groups (such as wide receiver and defensive line) but the Cardinals have achieved a rare feat in the NFL. They're returning every player who caught a pass from Palmer in 2015 and every player who scored an offensive touchdown last season. Having that type of continuity is rare, especially for a team that came one game away from the Super Bowl. By boasting so many returning players, the Cardinals don't have to spend as much time reteaching their offense. Instead, they can continue building on last season, making an already potent offense -- one that set franchise records for points, touchdowns, touchdown passes, total net yards, first downs and passing first downs and first downs passing -- even stronger. -- Josh Weinfuss

During the offseason, Rams coach Jeff Fisher repeatedly said the team planned to bring in a legitimate kicker who could push incumbent Greg Zuerlein for his job. At the March owners meetings, Fisher was even specifically asked if the kicker brought in would be "more than a camp leg," to which Fisher replied in the affirmative. By the end of free agency and the draft, the Rams added only one kicker, undrafted rookie Taylor Bertolet of Texas A&M. Bertolet profiles in similar ways to Zuerlein, which is to say he has a strong leg but accuracy hasn't exactly been his calling card. He made five kicks of 50-plus yards in 2015 but converted just 71 percent of his field goal tries. Whoever emerges with the job must offer more consistency. Last year, Zuerlein missed a field goal and an extra point in a three-point loss to Baltimore, missed a 48-yard field goal in an overtime loss to Minnesota and failed to convert two field goals in a three-point overtime loss to San Francisco. For as many close games as the Rams have a tendency to play, a strong, accurate field goal kicker could be the difference between their first winning season since 2003 or continued mediocrity. -- Nick Wagoner

Who will be the Niners' third-string quarterback? Yes, the guy holding the clipboard. We all know that Blaine Gabbert and Colin Kaepernick will battle it out for the starting gig but the third-stringer, who will run the scout team and should have an intimate knowledge of new coach Chip Kelly's offense, should be one of the more important job descriptions in Santa Clara. So will it be rookie Jeff Driskel, who was drafted in the sixth round out of Louisiana Tech, or Thad Lewis, who was signed as a free agent after spending time with Kelly in Philadelphia? Or might -- gulp -- the loser of the Gabbert/Kaepernick battle be sent out of town? Stay tuned. -- Paul Gutierrez

Will Michael Bennett's contract situation become a distraction? Last summer, strong safety Kam Chancellor held out of camp, missed the first two games of the regular season, and the Seahawks found themselves in an 0-2 hole. Bennett has two years remaining on his deal but has not been shy about expressing discontent with his current salary. He was one of the most disruptive defensive linemen in the league last season, posting 10 sacks and 19 tackles for loss. Will Bennett and the Seahawks be able to find a middle ground? Or will the organization be dealing with contract drama for the second summer in a row?-- Sheil Kapadia