Beyond Marcell Dareus, who can Bills re-sign next offseason?

The Bills would like to get a deal done with Marcell Dareus by the start of the regular season. AP Photo/Bill Wippert

The Buffalo Bills have locked up another young defensive player, announcing a contract extension Sunday for cornerback Nickell Robey.

Robey was set to become a restricted free agent next offseason, so his new deal checks one item off the Bills' to-do list following this season.

The terms of his deal haven't been revealed but his re-signing shouldn't dramatically alter the Bills' salary cap situation for next season. According to ESPN Stats & Information, and using a projected $150 million league-wide salary cap, the Bills have about $5.5 million of cap space for the 2016 season. That number should increase when the Bills carry over their unused salary-cap space from 2015, which is currently around $7.7 million.

With Robey now re-signed, here is a look at other Bills players set to become free agents next March:

DT Marcell Dareus -- Re-signing Dareus remains a priority for the Bills and they would like to get a deal done by the start of the regular season. It won't be cheap. Dareus is expected to command a deal somewhere between Gerald McCoy's contract, worth about $14 million annually, and Ndamukong Suh's pact, worth nearly $20 million per year. Even if the Bills were to keep Dareus' 2016 cap number low -- $10 million or less -- his re-signing is very likely to put the Bills over the projected salary cap for 2016, which will significantly hamper their ability to re-sign other free agents or sign players from other teams.

OT Cordy Glenn -- The Bills' left tackle could be a casualty of Dareus' deal. Rex Ryan mentioned last week that Glenn likely will command "left tackle money" but the Bills will be hard pressed to afford that under their current salary structure. Giving Glenn a big-money deal would also be a risk for the Bills because Glenn has proven to be a good -- but not great -- left tackle in three seasons with the team. The cheaper (and from this perspective, more likely) scenario is that the Bills let Glenn walk and draft a tackle in the early rounds next spring. That player would then compete with Seantrel Henderson for the left tackle spot next summer.

LB Nigel Bradham -- Like Glenn, the up-and-coming linebacker could also be entering his last season with the Bills. Once Dareus is re-signed, the Bills will have close to $50 million tied up in their starting defensive line next season, meaning they won't have much left over to commit to linebackers. Bradham has a powerful agent, Drew Rosenhaus, who could find him a better deal elsewhere. If Bradham departs in free agency, linebacker will vault to the top of the Bills' list of draft needs, behind quarterback and offensive tackle. Manny Lawson will be 32 next summer and entering the final year of his deal, leaving Preston Brown as the only long-term starter at the position. The Bills have drafted well at linebacker in recent years, picking up Bradham in the fourth round in 2012, Kiko Alonso in the second round in 2013 and Brown in the third round in 2014.

G Richie Incognito -- The Bills could be in need of a left guard next season if they can't find cap space to re-sign Incognito, who could make up to $2.25 million this season if he hits all incentives in his contract. Incognito signed a one-year deal that will allow him to explore his options next spring. He'll be 33 next July and won't be able to command a big-money, long-term deal but the Bills could still be in a tough position to match other offers.

QB Matt Cassel -- This is the wild card of the bunch. If Cassel becomes the Bills' starter, the team could renegotiate his deal -- currently set to pay him a $4.15 million base salary this season, the final year of the contract -- and keep him in town another year. That would be a gamble from both sides, since the Bills would have to find cap space to pay Cassel as their starter in 2016 and hope that he remains a viable NFL quarterback in his age-34 season. Cassel would also be taking a risk by accepting any Bills' offer early in the season because that would take away his leverage on the open market next spring. If Cassel doesn't become the Bills' starter, his $4.15 million base salary becomes a burden on the team and they could save valuable cap space (and carry it over into 2016) by releasing him prior to the start of the regular season. But in that case, the Bills would have to hope that either Tyrod Taylor or EJ Manuel finds his way this season because those will be their only two QBs under contract in 2016.

WR Percy Harvin -- Harvin technically is under contract through 2017 but those were essentially "dummy" years included in his contract to spread out the cap hits from his $3 million signing bonus. Harvin's deal calls for a $9 million base salary in 2016 but is voidable prior to the start of free agency next spring. Unless Harvin has a career year and the Bills decide that his $10 million cap hit is a bargain, they can release him and save $9 million. They could then make him a different offer or part ways.

RB Fred Jackson -- The Bills' team captain will turn 35 by the time he hits the open market next spring and it remains uncertain whether the Bills will re-sign him. If they do, it would have to be for very small money -- almost certainly less than his $2.7 million cap hit this season. Would Jackson, a future Bills Wall of Famer, consider work elsewhere? That's also uncertain. Right now, I would leave every option on the table.

CB Ron Brooks -- The Bills have an ideal fourth or fifth cornerback in Brooks, who contributes on special teams. He'll be an unrestricted free agent and won't be a priority for the Bills to re-sign.

DL Alex Carrington, RB Bryce Brown, WR Marcus Thigpen, FB John Conner, TE Matthew Mulligan, DT Andre Fluellen-- It's still uncertain if these players make the 53-man roster, but if they do, they will be unrestricted free agents after this season.

Restricted free agents: LB Ty Powell, WR Chris Hogan, DT Corbin Bryant, DT Stefan Charles, S Bacarri Rambo, TE MarQueis Gray, WR Deonte Thompson -- The Bills have a few valuable depth-level players -- particularly Powell, Bryant and Charles -- scheduled to become restricted free agents. The Bills can offer tenders to each of the players to protect their rights, but it will come at a cost. A first-round tender last spring was $3.3 million, a second-round tender was $2.4 million and an original-round compensation tender was $1.5 million. The low tender would be the most cost-effective but would only protect Rambo (a sixth-round pick) and Powell (a seventh-round pick). The others were undrafted free agents, so the Bills would receive nothing if another team matched the original-round tender.