Every free-agent signing is a risk. When a team goes outside its organization to add talent to its roster, it’s gambling on the player being both a scheme and culture fit. Even supposedly slam-dunk deals, like the one that Philadelphia gave to Nnamdi Asomugha in 2011, miss the mark from time to time. Asomugha was a proven shut-down corner and the top free agent in his class. He signed a five-year deal with the Eagles … and lasted two years in Philly before being released, signing with San Francisco, and retiring in 2013.

While Asomugha seemed an obvious signing for any team, each free-agent class includes guys for whom the risk goes beyond the baseline fit worry. We’re talking about the guys who have looked like game-breakers at one time or another but also carry concerns about injuries, motivation, inconsistency, or a year of outlying performance. However, talent is scarce in the NFL, so teams will talk themselves into the exception becoming the rule — and sometimes they’ll be right.

Here are the NFL’s 13 riskiest free agents for 2017.

Running Back: Adrian Peterson

Physically speaking, Peterson is a rarity, even when compared to the elite athletes of the NFL. He possesses otherworldly healing power, an apparently unquenchable thirst to play, and an unparalleled work ethic, so normal conventions about running back age curves might not apply to the Vikings all-time leading rusher. But Peterson’s almost 32, and when the running back cliff comes, it comes quickly.

It’s not just the age thing that should worry teams, either. Peterson’s a throwback runner, with almost 95 percent of his career carries coming out of traditional formations with the quarterback under center. Anyone who signs Peterson will either have to hope he’ll adapt well to the increasingly popular shotgun and pistol looks the league favors or abandon them when he’s on the field. But teams usually aren’t approaching free agency looking for players that will limit what they can do within their scheme.

Peterson may have something left in the tank, and in the right role, he could certainly provide value to an offense. But with his injuries and his somewhat anachronistic style of play, it’ll take an awful lot of projection and acceptance of the unknown to feel OK about signing the veteran back.

Running Back: Eddie Lacy

When Lacy’s healthy and fit, he’s a force to be reckoned with, mixing piston-like feet with tackle-breaking power and grace. We saw that his first two seasons in the league, as the 2013 second-round pick rumbled for 2,317 yards and 20 touchdowns. But his well-documented weight issues remain a major concern, and the injury worries always follow close behind. Lacy got off to a great start last year after reportedly losing around 30 pounds in the offseason, but after five weeks he’d reportedly gained a good portion of that weight back before he hit the injured reserve with an ankle injury in Week 6.

Even with the additions of Peterson and Jamaal Charles, it’s a weak running back market, so someone might look at Lacy’s 2014 tape and see a guy who can sustain a run game on early downs and function as a battering ram in the red zone, but if a team’s going to hand out anything more than a one-year deal, it might include the kind of weight-limit clause we typically only see with linemen.

Wide Receiver: Alshon Jeffery

Jeffery’s talent is undeniable, and 6-foot-3, 218-pound receivers with preternatural body control and hand-eye coordination don’t come onto the open market every year — especially when they are in their prime. Over the past four seasons, Jeffery has reeled in 280 passes (17th among all wideouts) for 4,182 yards (ninth) and 23 touchdowns (17th), but there’s one primary concern: availability.

The 27-year-old missed a quarter of last season serving a PED suspension and sat out seven games in 2015 with an assortment of soft-tissue injuries (groin, hamstring, calf). With Spotrac estimating the big receiver’s market value to be somewhere around $12.2 million per year — Jeffery will be looking at a deal in the vicinity of A.J. Green’s five-year, $60 million deal — that’s a lot of coin to be throwing down on a player who hasn’t been able to stay on the field the past two years.

Tight End: Jared Cook

Cook broke out for Green Bay in the second half of 2016, catching 30 passes for 377 yards and one touchdown in 10 appearances. His unbelievable sideline toe-touch grab against the Cowboys in the playoffs will be a great negotiating point for his agent this spring, as will his effectiveness up the seam on third downs. But a quality half-season catching passes from Aaron Rodgers, the hottest quarterback on the planet over the second half, doesn’t erase everything that came before it.

Cook struggled to stay healthy last season, missing six games with an ankle injury, and while he finally managed to curtail the drops that have plagued him his whole career — he dropped just two passes in 2016 after leading all tight ends in drops in 2015 (10) and 2013 (eight), per Pro Football Focus — this past season’s reliable hands represent the exception, not the rule. In a shallow tight end market, someone may see the big-play potential and athleticism Cook provides and overpay based on his ceiling, but they’d also be ignoring an otherwise underwhelming career up to last season. You know, the thing that forced him to play on a one-year deal for the Packers in the first place.

Offensive Tackle: Russell Okung

The five-year, $53 million contract that Okung negotiated last spring was essentially a one-year “prove-it” deal with a four-year option, but after one season, Denver apparently didn’t think he’d proved enough. The Broncos chose not to pick up the rest of the contract, sending Okung back to the open market for the second straight season. Starter-level left tackles don’t exactly grow on trees, and Okung is entering a relatively barren market for them. Combine that with a weak draft class at the position, and he’ll be one of the more highly sought-after (and well-paid) players at that spot. And yet, the Broncos let Okung walk without an obvious replacement lined up, just a year after the Seahawks did the exact same thing. Caveat emptor.

His injury history is one reason. Last year marked the first time in Okung’s seven-year career that he played in all 16 games, but his time in Seattle was marred with injuries ranging from high ankle sprains to toe injuries to a torn pectoral muscle to a shoulder injury. He wasn’t impressive on the field last year, either: He struggled with speed rushers and wasn’t as good in the run game as he’d been in Seattle.

Okung has the physical talent to be dominant, but because of injuries and inconsistency on the field, he’s failed to live up to his potential. At 29, he’s still young enough to be considered for a long-term deal, so there’s upside, but paying him top dollar (which will likely happen in this market) may have more risk than potential reward.

Offensive Tackle: Ryan Clady

The two-time All-Pro and four-time Pro Bowl left tackle may still have talent, and he’s still young enough (30 years old) for a team to take a shot on, but three of his past four seasons have been cut short by injury. He missed all but two games in 2013 with a foot injury, all of 2015 after tearing his ACL in OTAs, and seven games in 2016 with a torn rotator cuff. When healthy, Clady’s a dancing bear on the blind side — mixing brute strength with nimble footwork — and someone might throw money at him for the same reasons they would Okung, but it’s really hard to see Clady playing a full season at this point in his career.

Center: J.C. Tretter

Tretter is the top free-agent option at center, and he can play all five positions on the line in a pinch, which makes him even more valuable. However, a 2016 campaign that started out with a ton of promise was cut short after seven weeks when he sprained his MCL, highlighting an issue that’s plagued him as a pro. Tretter has started just 10 games for Green Bay in four seasons and missed major portions of three out of four years to injury.

When he’s been on the field, the versatile 26-year-old has been impressive, particularly in 2016. But there’s a lot of projection when it comes to Tretter because of the small sample size of his on-field résumé. With his injury history, will a team risk giving him starter money with major guarantees? Because of a shortage of quality offensive linemen throughout the league right now, it seems likely someone probably will.

Pass Rusher: Nick Perry

With Jason Pierre-Paul, Chandler Jones, and Melvin Ingram all getting the franchise tag, Packers outside linebacker Perry shoots to the top of the list for edge rushers in this year’s class. Apart from older situational rushers like Julius Peppers, Charles Johnson, Mario Williams, and Dwight Freeney, there’s … Jabaal Sheard? However you have those guys ranked, Perry stands out well above any of them after an 11-sack performance in 2016, and the 26-year-old is about the only guy left on the market that looks like an ascending talent. In other words: He’s gonna get paid.

Yet, whichever pass-rush-desperate team decides to give Perry a long-term deal to get after the quarterback will have to convince themselves that 2016 wasn’t a one-hit wonder. There’s a reason he was playing on a one-year deal in Green Bay in 2016: His previous high for sacks was just four, in 2013. Perry may end up among the best edge rushers in the league, and he certainly looked liked one last season. But Blind Melon should be playing in the head of anyone who’s interested.

Pass Rusher: DeMarcus Ware

There’s no doubt that Ware can still be a disruptive force on the edge — he grabbed four sacks and 26 total quarterback pressures in limited action in 2016 — and the nine-time Pro Bowler’s absolute floor is as an efficient situational pass rusher. But in order to do that, he’s got to be on the field: Ware suffered an ulna fracture near the elbow in Week 2 last year, causing him to miss the next five games, and his season was cut short by a ruptured disk in his back that required surgery after Week 16. Back injuries can be career-ending in this line of work, so while Ware still wants to play, the 34-year-old is a huge risk for any team willing to give him any major guarantees.

Related The Four Rules of NFL Free Agency

Linebacker: Lorenzo Alexander

Alexander is one of the most fascinating free agents in this class. He was an afterthought in last year’s free-agency period, signing with the Bills for the veteran minimum as a special teams ace. He contributed plenty in that role for Buffalo last season, but also racked up 12.5 sacks (tied for third in the league) as their best, most versatile pass rusher. He’s set to cash in on that out-of-nowhere career year.

Except, in nine seasons prior, Alexander had produced just nine sacks … total. Alexander’s 2016 season is the outlier of all outliers, but with few pass-rushing options available in free agency, the 33-year-old journeyman might find some interest. With the Bills starting the switch to a 4–3 defense under new coach Sean McDermott, Alexander may find a new home in a 3–4 defense looking to upgrade its blitzing capabilities. Perhaps Arizona, Pittsburgh, Washington, Cleveland, or San Francisco will pick up the phone.

Cornerback: Morris Claiborne

Claiborne finally managed to scratch his star potential for the Cowboys in 2016, looking ever so briefly like a shutdown corner — before his regular season ended after seven games with a groin injury. (He played 26 snaps in the divisional-round loss to the Packers.) Teams in need of cornerback help have to ask themselves whether his high-level play last season was an anomaly from an otherwise forgettable career, or the signal that the 2012 sixth-overall pick had finally figured it all out.

It’s not just a question of whether he’s an ascending player or not, either. He’s been a constant injury concern as a pro and has played in just 32 of 64 possible games over the past four seasons. Claiborne’s potential as a free-agent acquisition is sky high, but there’s nobody with a lower floor, either.

Cornerback: Stephon Gilmore

Gilmore’s one of the most physically gifted cornerbacks on the free-agent market, and at 6-foot-1, 190 pounds, the 26-year-old has prototypical size. Except, he’s yet to put together a full season of top-level play. That inconsistency will have teams digging deeper into whether he’s worth big-time cornerback money in the vicinity of the $14 million-or-more per year that Spotrac has him pegged at.

Last year was a microcosm of Gilmore’s career to this point: He started the year terribly, and after a poor showing in Buffalo’s 41–25 shellacking by the Patriots in Week 8, head coach Rex Ryan called him out publicly for his poor play. Gilmore bounced back after that to finish the season strong, including a two-interception performance two weeks later. Some teams will use the strong second half as a reason to sign him; others will wonder why he couldn’t do it over 16 games.

Safety: Johnathan Cyprien

In 2016, Cyprien emerged as a force in the run game and played his best ball in his contract year with the Jaguars, racking up 126 tackles (most among safeties) and a 98.8 run defense grade per Pro Football Focus (also tops at his position). However, there should still be concerns for a team considering dishing out upper-tier-safety money to the fifth-year pro.

For one, Cyprien’s still a bit of a liability in coverage — the 58th-graded pass defender among safeties per PFF — and his high-impact play around the line of scrimmage only just showed up this season. Plus, with the NFL draft about to feature one of the most talented safety classes in recent history, teams might think twice about putting too many guarantees into Cyprien’s deal. Finding run defenders in this league is relatively easy and cheap. The safeties who can also cover are the ones who can have the most impact and make the most money in an increasingly pass-happy league. So unless there’s a specific role in the box that a team desperately needs — and because it’s a pass-happy league, those needs are diminishing — most franchises should be able to find better value elsewhere.