The NFL is about to embark on the most frantic free-agent period in its 18-year history. The schedule for acquiring new players has been compressed, giving teams all of 10 days to complete a free-agency process that usually takes a month. Prime targets identified back in February have been wallowing in limbo. Unlike every other year, coaches and general managers won’t have the benefit of a draft to patch up the spots they missed in free agency; if a franchise misses out on the player(s) it wants, it will be forced to wait until the post-training camp cuts to shore up its weakest parts.

Depending on which side you’re on, then, it’s either ironic or terrifying that this year’s group of free agents is pretty bad. There’s only one Can’t Miss in the entire market. The core of the market is a group of flawed tackles: too fat, too slow, too old, too young, too inexperienced, there are valid critiques for every one of them. Owners looking for a dynamic playmaker to excite a jaded fan base are going to find them few and far between. The quarterback crop looks like an erstwhile fantasy team from 2007.

And yet, with the implementation of a harder salary floor that forces all teams to hit $89 million or so in real spending, even the league’s cheapest franchises will have to spend their money somewhere.

The lockout may have cost the broader population of the NFLPA some money going forward, but after four months of general managers’ frothing at the mouth to sign players, the free-agent pool is going to get a one-time exemption. These guys are going to get paid.

This preview includes unrestricted free agents; restricted free agents, players locked up with the franchise tags, and likely-to-be-released players have not been included. All of the individual defensive numbers and target data in this piece come from the charting project compiled by Football Outsiders volunteers.

FIVE OVERRATED PLAYERS

Ray Edwards, DE

Edwards hasn’t seen a double-team since college, thanks to playing alongside the Williams Wall and Jared Allen in Minnesota. As a result, he’s accrued 21 sacks over the past three seasons while lining up against overmatched right tackles and the back end of pass blocking schemes designed to stop Allen. The Vikings locked up backup Brian Robison, so they have every intention of letting him hit the market. If a team like Cincinnati signs him to be its primary pass-rusher, they’re going to end up sorely disappointed.

Braylon Edwards, WR

Braylon Edwards has built his argument for being a great pro receiver upon being selected in the top five by the Browns after a very good college career and a huge four-game stretch against terrible pass defenses in 2007. He’s a highlight-reel player, but he doesn’t run great routes and drops way too many passes to justify a big salary.

Jason Babin, DE

Babin put up 12.5 sacks with the Titans last year after accruing just 17.5 sacks through his first five pro seasons. At 31, chances are that he just had a fluke season, and he wants prospective bidders to give him a multiyear contract. Only the truly desperate can justify making such a move. His closest historical comparables are players like Mike Hartenstine and Rod Martin. Both Hartenstine and Martin dropped off to seven sacks in the season after their career year, and they didn’t reach beyond five sacks in a season after that.

Ike Taylor, CB

Taylor is 31 and has never been effective enough to make the Pro Bowl as a member of the Steelers. He is exactly the sort of veteran Steelers player to avoid in free agency.

Marc Bulger, QB

Somehow Bulger saw his stock rise dramatically by spending a full season on the bench in Baltimore, as talent evaluators began to remember his brand, while forgetting his recently poor level of play. Remember that this is the same 34-year-old who has exactly one healthy pro season to his name. If we take Bulger’s final three seasons in St. Louis and express them as a 16-start line, he went 280-of-487 (a 57.5 completion percentage) for 3,008 yards, with 12 touchdowns and 16 interceptions. Nobody with his record of injuries was able to come back into a starting job after moving to the bench. He’s a backup on merit.

FIVE UNDERRATED PLAYERS

Jacob Ford ranked second in each of the Top 25 Prospects lists I put together for Football Outsiders, ranking just below Miles Austin in 2009 and Mike Wallace in 2010. Ford tore his Achilles in training camp as a rookie, but he came back to record 12.5 sacks as a reserve in 2008 and 2009. He had a shot at the starting gig last season before getting hurt again in the preseason. By the time he came back, Jason Babin had his job. Ford’s going to be an undersized pass-rusher somewhere in 2011, and if he gets enough playing time, he’s capable of double-digit sacks; his career path isn’t all that dissimilar from Charles Johnson, who hit 11.5 in his first full season last year. He’s even money to pick up more sacks than Babin this year.

Mathias Kiwanuka showed bursts of brilliance as a pass-rusher with the Giants, but New York bounced him between defensive end and linebacker and never gave him the regular reps he needed to break out. As a situational pass rusher off the bench, Kiwanuka started 2009 with four sacks in three games before going down with a season-ending herniated disc in his neck. If his neck is close to 100 percent, he should be starting somewhere. His best position is probably as a 3-4 outside linebacker, which could make him a good fit for the Chiefs or Patriots.

Jerome Harrison has done nothing but produce. In 2009, after blowing away Jamal Lewis’ numbers as the primary backup in Cleveland, the Browns tried him out for five games as the primary back. He picked up 734 yards on 151 carries in those games (4.9 yards per carry), scoring five times. Eric Mangini was apparently underwhelmed, and the franchise drafted Montario Hardesty in the second round while acquiring Peyton Hillis in a trade with the Broncos. Hillis got the job after Harrison fumbled against the Chiefs in Week 2, and Harrison ended up getting dealt to the Eagles. In his two games with significant action as an Eagle, he gained 208 rushing yards on 20 carries. Someone give this guy a job already.

Davin Joseph has gone underappreciated by virtue of suiting up for the small-market Buccaneers; when he’s been healthy, he has been one of the best guards in football. He’s been bothered by repeated foot injuries, but a proactive medical staff like the unit in Dallas or Minnesota should be able to keep him on the field. Having already made it to the Pro Bowl in 2008, Joseph should make a return trip at least once during his next contract.

Matt Leinart was benched for a Hall of Fame quarterback and waived last year by a coaching staff that actually believes in the professional viability of Derek Anderson as a starting quarterback. There’s no guarantee that Leinart’s ever going to show the form that made him the 10th overall pick in 2006, but he’s more deserving of another shot than, say, Kyle Boller.

FIVE BUY-LOW OPPORTUNITIES

Stephen Bowen took over at defensive end last season for the Cowboys after Marcus Spears suffered a calf injury. He wasn’t exactly elite, but Bowen held his own as a starter on a bad team, producing seven hurries in the team’s final eight games. At 27, Bowen still has fresh legs, and his prototypical size (6-foot-5, 300-plus pounds) suggests a player who could break out with more playing time and experience.

Mark Clayton got caught up in a numbers game in Baltimore, which seemed more interested in stockpiling mid-30s wideouts than giving Clayton, who had just turned 28, another chance to start. He eventually found his way to St. Louis at the end of training camp and struck up an instant rapport with Sam Bradford, catching 23 passes for 306 yards over the first five games of the year before tearing his patellar tendon and going on injured reserve. Clayton works better in a short-passing offense than the deeper routes that the Ravens run, and if he’s healthy, he could contribute as an above-average no. 2 wideout.

Leroy Harris played well enough as a utility lineman in 2009 for the Titans to let future Hall of Fame center Kevin Mawae fade into retirement. The move opened a spot up for Harris at left guard, but he struggled with an ankle injury and failed to create lanes for Chris Johnson. According to the Adjusted Line Yards metric, only the Lions got less out of their offensive line in the running game than the Titans, and Harris was the only new starter on a line that had been dominant with Mawae in the lineup. Now that he’s got a year of experience underneath him, 2011 should be a better season.

Tommie Harris was once the league’s most dominant defensive tackle. In 2006, he was the best player on the Bears defense that ended up taking Rex Grossman to the Super Bowl. Harris missed the playoffs that year with a ruptured hamstring, and after playing through knee problems the following season, he simply hasn’t been the same player. The Bears benched him last season and released him before the lockout. The old Tommie Harris is probably gone, but a team with a great medical staff and low expectations might be able to get 20 very good snaps a game out of him.

Richard Marshall deserved a contract extension after the 2009 season. After moving into the starting lineup at right cornerback for the Panthers, he helped them put up the league’s second-best pass defense. Unfortunately for Marshall, the Panthers were busy extending Jake Delhomme’s deal, and while they only fell to eighth in pass defense last season, Marshall shouldered a lot of the blame. He’s still just 26, and he’ll catch on somewhere as a well-rounded corner capable of playing both outside and in the slot.

FIVE VETERANS WITH SOMETHING LEFT IN THE TANK

David Akers missed those two field goals in the wild-card game against the Packers. Bummer. The Eagles drafted Alex Henery in April to eventually replace Akers, but the veteran responded by hitting 25 of his last 27 regular-season field goal attempts. Akers was also the primary contributor on the league’s seventh-best kickoff unit. It’s unclear whether his transition tag will make it through the new CBA at the time of writing, but some team with a long memory is going to get a very good kicker.

Raheem Brock was the guy-behind-the-guys in Indianapolis, the undersized utility lineman who cleaned up when Dwight Freeney and Robert Mathis missed the quarterback. He never accrued a huge sack total in his time there, but last season in Seattle, Brock picked up nine sacks without starting a game. That included 2.5 sacks in the playoff-clinching win over the Rams. He might not be able to do that again, but he should be a solid situational pass rusher for a 4-3 team that needs one.

Clinton Portis has missed 19 games over the past two years, thanks to a concussion in 2009 and a separated groin last season. Although it seems as if he’s been around since the first edition of Tecmo Bowl, Portis will only turn 30 in September. When he’s been healthy, Portis has maintained a healthy 4.1-yard rushing average, and he’s one of the league’s best pass-blockers out of the backfield. He could be a valuable part of a running back rotation somewhere.

Billy Volek probably deserved a better career than the one he got. In what amounts to about one full season as a pro, he’s completed 60.1 percent of his passes while throwing 27 touchdowns against 15 interceptions. He just ended up in the wrong places, serving as the backup for Steve McNair. He got one extended run as a starter in 2004, and put up a quarterback rating of 87.1, 13th amongst NFL starters. When McNair left in 2006, the Titans gave the job to Kerry Collins and drafted Vince Young, so Volek was dealt to San Diego, where he was stuck behind another one of the league’s toughest quarterbacks, Philip Rivers. Maybe there’s nothing there, but Volek seems like a better option than some of the more prominent quarterbacks on the market.

Pat Williams took a step backwards at 37 last season, but it was from very lofty heights; Minnesota still ranked eighth against the run by DVOA, and Williams still contributed seven tackles for a loss or no gain. Some smart team is going to bring him in and spot his snaps effectively, and they’ll get a great run-stuffing tackle as a result.

FIVE BANDWAGONS TO JUMP OFF

James Jones is another example of the high-risk-player types profiled in the Free Agents You Meet in Hell, a secondary wide receiver from an elite passing offense. The book on Jones is public knowledge by now: great athletic ability, occasionally brilliant play, and oodles of drops. Is that really going to get better when Jones is a primary receiver and has tighter coverage on him?

Danieal Manning is rightly regarded as one of the league’s best kickoff returners, and as a starter on one of the league’s best pass defenses this year it seems odd that the Bears wouldn’t devote serious resources to re-signing him. But Manning really isn’t all that great of a safety; the Bears have spent most of his career trying to find somebody to replace him. Considering how effective Devin Hester has been on returns over the years, it’s pretty safe to say that the blocking and scheming of Chicago’s special teams may have had a lot to do with Manning’s past success.

Shaun Smith is the Vinnie Jones of (American) football, just without the comedic turns in Guy Ritchie movies. First, it was getting into a fistfight with Brady Quinn when they were both on the Browns. Last year, he was accused of junk-grabbery by two different offensive linemen in consecutive weeks. Around the league, he’s regarded as one of the game’s biggest shit-talkers, which says a lot in a league full of shit-talkers. He’s already received one steroid suspension. This all wouldn’t be a problem if he was any good, but Smith’s just a big body without any history of production. At least Jones won an FA Cup.

Steve Smith of the Giants is coming off of an extremely complex microfracture operation on his knee that involved damage to his articular cartilage. It’s a rare injury for a football player, and significantly affects Smith’s short-term value and long-term viability. Teams can handle players with ACL tears and broken bones because the recovery process is familiar. This is something totally different.

Darren Sproles has tantalized teams for years with his elite speed and ability as a return man. The Chargers kept him off the market at great cost for each of the past two seasons, but haven’t gotten all that much over that stretch, as Sproles has put up just 247 offensive touches at about a league-average level of play. San Diego seems convinced that Sproles can’t handle a workload much bigger than that, and he was one of the lead men on the worst special teams unit in football last season. He’ll always have that playoff game against the Colts, but a DVD of the game would be a lot cheaper than signing the real thing.

TIER 4 — The likely-to-be-average players with some upside.

Antonio Cromartie is perpetually overvalued. He’s always going to have a reputation as a ball hawk because of that 10-interception season in 2007, but he’s had eight picks since then, and not because teams have been avoiding him. Playing in a Rex Ryan defense with Darrelle Revis on the other corner would make a lot of guys look good. He’s a no. 2 corner who might command no. 1 money.

Brandon Mebane could be one of the bargains of free agency. At 310 pounds, he has the size to serve as a 4-3 defensive tackle or a 3-4 defensive end, and while his best work comes against the run, there might be some ability as a pass-rusher waiting to break out — Mebane had 5.5 sacks in 2008, and while he had only a lone sack last season, he added 11 quarterback hurries. At 26, a team like Chicago or Washington could be acquiring a future Pro Bowl lineman about to enter his peak years.

Stephen Tulloch is a middle linebacker cut from a different cloth than the other middle linebackers on the market, Barrett Ruud and Paul Posluszny. While Ruud and Posluszny are built to defend the medium zones in pass defenses, Tulloch is a bruiser who does his best work against opposing run games. He has some issues as a tackler. Opposing players broke 14 of his tackles last season, the highest rate in the league among linebackers. Rumors have linked him to the revolution fostered by former Titans defensive coordinator Jim Schwartz in Detroit. Denver could also target him as part of its defensive rebuild.

Harvey Dahl is widely regarded as one of the league’s nastiest human beings. Like Tyson Clabo, his next-door neighbor on the right side of the Falcons line, Dahl is a big body who emerged from relative obscurity in 2008. The Patriots have gotten great work out of nasty guards like Stephen Neal in the past, and with Neal’s retirement this offseason, they have a hole at right guard in the short-term.

Marshal Yanda moved outside to play right tackle for the Ravens last season because Jared Gaither spent the entire season on the sidelines with a back injury. Both are free agents now, and the Ravens appear inclined to re-sign Yanda and let Gaither hit the streets. Gaither was a promising left tackle as recently as 2009, but Baltimore moved Michael Oher to that side. At 6-9 and 340 pounds, Gaither has prototypical size, but his technique is still a work in progress. He’s also just 25. Yanda tore his ACL, MCL, and PCL in 2008, but he’s made a full recovery and looked good at tackle last season. His best position is out at guard, but he’s going to get paid to play right tackle, if only because it’s much harder to find a tackle than a guard.

Jermon Bushrod is the first of several left tackle options on the market. Having started 30 games over the past two years in one of the league’s best offenses, the 26-year-old should seemingly rate out as a prime talent, but the Saints succeed in spite of Bushrod, not because of him. Drew Brees makes him look good with great footwork and a lightning release that keeps opposing pass-rushers away, even if they’ve already beaten Bushrod at the line of scrimmage. Consider that Bushrod allowed four sacks and 14 quarterback hurries last season with his blown blocks; a slower quarterback like Jason Campbell or Jake Delhomme would have taken twice or even three times as many sacks in those same situations. Bushrod is likely to be a disappointment in his next stop.

Matt Hasselbeck is the best quarterback available until Donovan McNabb gets released by the Redskins. Although Hasselbeck is extremely brittle and prone to disastrous multiple-interception stretches, he still has most of his arm strength and could help tutor a younger quarterback. If he moves on from Seattle, he would actually be a great option to start ahead of Cam Newton this year in Carolina.

DeAngelo Williams got off to an incredible start as a pro. The only guy since the merger with a better rushing average in his first four seasons than Williams was Bo Jackson (minimum: 500 carries). Williams is coming off of his fifth season, though, in which he averaged just 4.1 yards per carry and missed the last 10 games of the year with a foot injury. Jonathan Stewart is now comfortably ensconced as the top back in Carolina, and the team has pressing needs elsewhere. Williams will move on to Denver or Miami as their featured back, but buyer beware.

Dawan Landry has had the benefit of playing his entire career alongside future Hall of Famers Ray Lewis and Ed Reed, which goes a long way. Since Reed does all the freelancing, Landry’s job has mostly been to do whatever it is Reed isn’t doing at any given time. He’s best attacking the line of scrimmage and helping out against the run. He’s been linked to Dallas after former Ravens defensive coordinator Rob Ryan signed there, but a more likely landing point for him would be St. Louis, where Steve Spagnuolo needs to replace the departed O.J. Atogwe.

Sidney Rice deserves better. Before Rice’s breakout 2009 season, the Vikings tried to sign T.J. Houshmandzadeh, but Housh bailed on them for Seattle. Then they drafted Percy Harvin to limit Rice. Instead, Rice caught 83 passes for 1,312 yards while becoming Brett Favre’s favorite receiver. Favre left last year, and Rice missed most of the season with a hip injury, coming back at less than 100 percent for the final five games. Teams will throw out the 2010 campaign and just focus on that mammoth 2009 season, but Rice has been injured in three of his first four pro seasons. He’s only 25, but consistent injuries may prevent Rice from ever being that 2009 player again.

TIER 3 — The above-average starters.

Since we’re getting into the top players on the market, we’ll expand our coverage here to note the best and worst qualities of each player. And while players don’t always make the most logical choices in free agency, we’ll find an ideal fit for each of the players in our top three tiers.

The Three Tackles: Jammal Brown, Tyson Clabo, and Doug Free

Why: Each of our tackles has a case for being the top option on the market. Brown has the best reputation, with two Pro Bowl appearances for the Saints (2006, 2008). He has the longest record of looking like an elite pass-blocker. Clabo is the ass-kicker on the right side of the line, the elite run blocker who built himself up into an NFL success after years of bouncing around practice squads. His pass blocking has improved markedly over the past couple of seasons, leading to his first Pro Bowl berth last season. And Free just had an excellent debut season as the Cowboys’ starting left tackle. He allowed just three sacks, which was half the total allowed by Flozell Adams at the same spot in the previous season. The rest of the team allowed 28 sacks last year. At 27, he should be entering his prime now, and with just 23 starts under his belt, he should be healthier than most tackles at a similar age.

Why not: They also all have obvious flaws. Brown had major hip surgery in 2009 and missed the entire season, and his hip continued to give him trouble last year, when he suited up at right tackle for the Redskins. Clabo is already at right tackle and isn’t a great athlete, so as he ages, he’s probably going to have to move inside and play right guard, where he isn’t as valuable. As for Free, well, he’s only got one year under his belt as a starter. Do you really want to offer $10 million a year to a guy who might have been a flash in the pan?

Where to: Brown is going to need some team to convince itself that his hip will hold up. Buffalo and Arizona both desperately need left tackles, and Cincinnati might be ready to give up on oft-injured prospect Andre Smith and sign a veteran. Free is likely going to stay in Dallas, which has holes up and down the line and only one young asset in 2011 first-round pick Tyron Smith. Clabo would be an ideal fit for Tampa Bay, which needs a right tackle to replace the disappointing Jeremy Trueblood and could take Clabo away from a division rival in the process. Free agency is treacherous fun.

David Baas, C/G

Why: Baas took over at center for the 49ers after expected starter Eric Heitmann fractured his fibula in training camp; despite spending his entire NFL career at guard, Baas ended up as one of the few pleasant surprises for the league’s most disappointing team. With Ryan Kalil given the franchise tag by Carolina, Baas represents the only long-term option at center available on the market.

Why not: Baas has only one year at center underneath him. Although he is capable of playing guard, he wasn’t particularly effective there. He is likely to be overpaid because of how scarce the position is at the moment.

Where to: San Francisco, which has placed a clear emphasis on building through the offensive line and loves the idea of having Baas next to promising guard Mike Iupati for the next few seasons.

Robert Gallery, G

Why: Gallery’s an example of why taking a left tackle can be one of the draft’s safest picks. Even though he never developed into the elite tackle that the Raiders hoped for after taking him with the second overall pick, Gallery’s been able to shift down the offensive line spectrum to left guard, where he’s an excellent run-blocker and able in pass protection. When a quarterback busts in the top five, their next job is becoming a college coach or a UFL star.

Why not: Guards who can run block really aren’t that hard to find, and Gallery’s name is going to tack a few million dollars onto his deal. He’s missed 18 games over the past two seasons with injuries, and he’ll be 31 before the season starts, so he’s not about to suddenly get healthy.

Where to: Seattle has a gaping hole at left guard and former Raiders head coach Tom Cable running the offensive line.

Roman Harper, S

Why: Advanced defensive statistics are a work in progress, but Harper allowed an average of just 3.8 yards on the 35 pass attempts in which he was the primary defender. Among defensive backs with 30 targets or more, only Asante Samuel and fellow Saints safety Malcolm Jenkins had a lower YPA figure. Harper’s also excellent in run support, having made 98 tackles last season against only five whiffs. Last season was his second consecutive Pro Bowl campaign.

Why not: Harper might have had the worst game of his life in the playoff loss to Seattle. He was the primary defender in coverage on each of Seattle’s three touchdown passes in the first half. Later on, he lollygagged for most of Marshawn Lynch’s invincible run. Not the best way to enter free agency.

Where to: The league’s worst defense last year was Jacksonville, a team that also needs to spend to hit the new salary floor. Harper would be a huge upgrade on Courtney Greene at strong safety.

Cullen Jenkins, DE

Why: As teams continue to move to the 3-4, players like Jenkins become more valuable. Defensive linemen between 270 and 290 pounds are rapidly becoming tweeners in most 4-3 schemes, but the 290-pound Jenkins is a perfect fit to play defensive end in the 3-4. He’s thrived there since Dom Capers installed the 3-4 in Green Bay two years ago, and while he’s not expected to accrue huge sack totals at the position, Jenkins took down the quarterback seven times in just 11 games last season.

Why not: Jenkins has struggled to stay healthy, having started 16 games just once in his pro career. He’s missed 17 games over the past three seasons thanks to a torn pectoral in 2008 and a nagging calf injury last season. (He also played through a broken hand.)

Where to: Washington desperately needs talent up front on defense. Jenkins has to be their top priority in free agency, and as you may already be aware, Daniel Snyder is very good about getting his man.

Charles Johnson, DE

Why: Johnson is best pass-rusher available in unrestricted free agency. He had 10 sacks as a pass rushing specialist off the bench in 2008 and 2009, and then followed that with 11.5 sacks while replacing Julius Peppers last season. Eight of those sacks came during the second half of the season, which could be a sign that he really improved as the season went along. His 46 quarterback hurries also ranks among the league leaders. Johnson just turned 25, and he has no injury history to speak of.

Why not: Ten-plus-sack defensive linemen don’t often sustain their performance in the season after their arrival. Johnson is still learning his craft and isn’t particularly effective against the run.

Where to: Carolina should have franchised Johnson, but they locked up center Ryan Kalil instead. They should still end up re-signing him, but it’s going to cost them a lot more than it should have. If Johnson does leave, Cincinnati, Tennessee, and even Philadelphia could be in play for him.

Zach Miller, TE

Why: The best tight end on the market, Miller has managed to repeatedly put up above-average catch rates despite playing with JaMarcus Russell, Bruce Gradkowski, Charlie Frye, and other misfit toys at quarterback. After accounting for the length of his routes, the down and distance, and the accuracy of his quarterback, Miller’s caught close to 30 passes more than an average player in the same spot would have over his four-year career. He’s also a sure blocker, which makes him the best offensive player the Raiders have.

Why not: Tight end remains a remarkably easy position to find quality talent at.

Where to: Oakland is desperate to hold onto Miller, and with Asomugha’s contract coming off the books, they’ll have the cap room to make him the highest-paid tight end in football.

Paul Posluszny, LB

Why: A speedy middle linebacker coming off of a bad season, Posluszny represents a great buy-low opportunity. He struggled mightily when the Bills moved to a 3-4 before the season, but his performance improved after the team started returning to 4-3 looks in October. He could end up a lot like Jonathan Vilma, who struggled under the Jets’ 3-4 and flourished upon arriving in New Orleans, which uses a 4-3 alignment.

Why not: Like Ruud, Posluszny is a Cover-2 middle linebacker at a time when the Cover-2 is going out of the style and the 3-4 is in vogue. He gets caught up in trash way too easily and makes too many of his tackles too far from the line of scrimmage. Posluszny has also missed nearly 30 percent of the games he’s been eligible to play in as a pro because of injury.

Where to: Giants defensive coordinator Perry Fewell had the same job in Buffalo, and the 4-3 scheme he’s running is a great fit for Posluszny’s skills. Posluszny could play middle linebacker or even move outside, as the Giants need a lot of help at the second level.

TIER 2 — The borderline Pro Bowlers.

Aubrayo Franklin, DT

Why: Because he doesn’t rush the passer or accrue stats in his role as the nose tackle in the 3-4, Franklin has flown under the national radar. He lacks the elite athleticism of Haloti Ngata or the massive frame of Albert Haynesworth, but no interior lineman in football is better at reading blocking schemes and manipulating the offensive front. He creates double-teams by occupying two offensive linemen on most plays, freeing up Patrick Willis to make plays behind him. It’s safe to say that he’s popular with his teammates; as Willis noted during the 2010 offseason, “I pray to God they keep Aubrayo.”

Why not: Franklin really has only two seasons of dominant play underneath his belt, and they both came in contract years. (Franklin was franchised by the 49ers after the 2009 season.) The 49ers are trying to get the word out that Franklin’s 2010 season wasn’t all that great, but if he did slip, it was only because he was downright incredible in 2009.

Where to: Kansas City, which tried to get by with overmatched veteran Ron Edwards at the nose last year and saw its run defense fall apart during the second half of the season as a result. Washington could also be involved here.

Santonio Holmes, WR

Why: Holmes took over as the Jets’ top receiver after he came off of his suspension. His 78 targets during the final nine weeks easily surpassed Braylon Edwards’s total of 59. He finished the season with a catch rate of 54 percent, which actually looks pretty good considering how deep his routes normally go and the accuracy issues of Mark Sanchez. The plus-minus system I developed during my time at Football Outsiders suggests that he caught 3.3 more passes than an average receiver would have, given the same targets with the same quarterback throwing them. You know how fast he is already.

Why not: Holmes is only a year removed from being dumped by the Steelers for pennies on the dollar. He will command a contract commensurate with that of a no. 1 wideout, but his career as the top guy in a passing offense consists of one half of one season in a below-average passing offense. He’s probably overvalued because of his huge Super Bowl XLIII performance.

Where to: The Jets, who rightly see him as their second-best free agent. Holmes is ahead of Braylon Edwards and Antonio Cromartie, but behind the franchised David Harris.

Johnathan Joseph, CB

Why: Leon Hall and Joseph very might well be the league’s best pair of cornerbacks, but both toil in obscurity because they play for the Bengals. As a sign of how good the team’s coverage was, consider that the Bengals had the league’s 14th-best pass defense despite sacking the opposing quarterback on just five percent of dropbacks, the fifth-lowest rate in the league. Joseph isn’t in Nnamdi Asomugha’s league as a cornerback, but he’s nearly three years younger, so his deal may return more value in 2013 and beyond.

Why not: Joseph has spent virtually his entire career playing alongside Hall, a cornerback who is every bit as good as he is. It’s likely that he’ll end up moving to a team that expects him to be their no. 1 cornerback, and there are no guarantees that he’ll look as good. The Bengals have reportedly chosen to save their money for Hall’s impending free agency next season, which tells you that the Bengals don’t really value Joseph. He’s also missed 12 games over the past three years, primarily with foot and ankle injuries. Those tend to linger.

Where to: Houston, assuming Nnamdi Asomugha ends up heading somewhere else. Coach Gary Kubiak and general manager Rick Smith probably need to make the playoffs in 2011 to hold onto their jobs. Adding a cornerback like Joseph is the quickest way for them to upgrade the league’s worst pass defense.

Barrett Ruud, MLB

Why: Ruud’s one of the best pass-coverage linebackers around. That skill is very important in a league that’s throwing more passes than ever before. Having spent his career operating at the base of a Cover-2 defense, Ruud has the speed to get up the field with even the fastest tight ends — consider that he held blazing Saints tight end Jimmy Graham to three catches and 26 yards in two games last season. He’s been durable, missing just one game as a pro.

Why not: Ruud isn’t considered an effective defender against the run, taking some of the blame for a unit that ranked dead last in DVOA against opposing rushing attacks last year. The defensive tackles in front of him did terrible work, but last is still last. The Bucs have refused to grant him an extension in each of the past two offseasons, so it’s pretty clear that they’re comfortable moving on despite lacking an obvious replacement.

Where to: Cleveland needs to spend to hit the cap floor, is moving to the 4-3, and has a major hole at middle linebacker, where oft-injured D’Qwell Jackson is a free agent. Ruud’s an ideal fit.

Eric Weddle, S

Why: He’s been cursed to play his first four seasons in the same conference with two future Hall of Famers at his position, but Weddle really isn’t far off from the standards set by Troy Polamalu and Ed Reed. He doesn’t have the signature hitting power of Polamalu or the otherworldly range of Reed, but he’s a harder hitter than Reed and is better in coverage than Polamalu. Weddle hasn’t been in a role to freelance as frequently as those two, but he also hasn’t had as good of a defense around him, either.

Why not: Safety is generally a low-impact position, so shelling out a lot of money to acquire one isn’t necessarily a great idea. Weddle’s been relatively healthy so far, but it’s rare to find a safety who doesn’t start missing time with injuries as he gets older. He doesn’t have a single transcendent skill; Weddle is the guy who gets a B+ in everything.

Where to: Tampa Bay needs to spend more than $46 million this offseason to hit the new salary floor. They’ve spent years longing for a replacement for John Lynch, and while rookie Cody Grimm showed some promise last season before fracturing his fibula, Weddle would be an enormous upgrade on Sabby Piscitelli and Sean Jones.

TIER 1 — The true franchise player.

Nnamdi Asomugha, CB

Why: Arguably the best player at any position in football over the past four seasons, Asomugha has been thrown at just 92 times over that stretch, which is less than half as frequently as any other regular starter in football. No cornerback of this generation plays the angles on the outside any better — Asomugha has mastered the subtle art of staying close enough to his assignment while simultaneously reading the quarterback. Despite sometimes being referred to as a “cover corner” because he never has to tackle anybody, Asomugha is, in reality, great in run support and truly fearless. When the Broncos ran a screen pass to 325-pound tackle Ryan Clady in 2009, Asomugha calmly stepped up and chopped Clady’s legs out from underneath him.

Why not: Asomugha peaked in 2008 and 2009, so whoever signs him is paying for the downside of his career. He turned 30 in July and will eventually end up moving to safety, although he could end up having a Rod Woodson-esque second career there. He might intimidate his teammates in the same way that you get intimidated by talking about music at a party to someone who knows a lot more about music than you.

Where to: Philadelphia, which has a huge hole across from Asante Samuel, is comfortable spending on players at the top of the market, and fulfills Asomugha’s desire to play for a winner.

Bill Barnwell is a staff writer for Grantland. Follow him on Twitter at @billbarnwell.