Eight in the Box: Must-keep free agents

Welcome to "Eight in the Box," a new NFL Nation feature that will appear each Friday during the offseason. This week’s topic: Which free agent is essential for each team to keep from its 2012 roster?

Buffalo Bills: Safety Jairus Byrd. The Bills are undergoing a defensive makeover. They recently released three veterans on defense -- Nick Barnett, George Wilson and Terrence McGee -- but Buffalo cannot lose Byrd. He is Buffalo’s best defensive playmaker. Byrd has 18 interceptions and 10 forced fumbles in the past four seasons; he will get a lot of interest if he hits the open market. But Buffalo most likely will use the franchise tag if both sides cannot reach a long-term agreement.

Miami Dolphins: Wide receiver Brian Hartline. The Dolphins have various quality free agents. But out of a deep group, Hartline would be the most important. Miami needs to add receivers, not lose them. Hartline led Miami in receptions (74) and yards (1,083) last season. The Dolphins will look to sign a true No. 1 receiver, possibly Greg Jennings or Mike Wallace. Re-signing Hartline would be a solid No. 2 option. As usual, it's going to come down to money.

New England Patriots: Wide receiver Wes Welker. The Patriots have several important free agents. Sebastian Vollmer is a top right tackle. Aqib Talib is easily New England’s best cover corner. However, none of them matches up to the production of Welker. He is the glue that makes New England's offense work. He recorded his fifth 100-catch season for the Patriots, and it's hard to see anyone making up for that kind of production. It's probably a 50-50 chance Welker stays. The Patriots have played hardball with Welker for more than a year now and most likely won't overpay to keep him.

New York Jets: Tight end Dustin Keller. Keller is not New York's best free agent, but he is the most important. New York's passing game was mostly horrendous last season without Keller in the lineup as the quarterback's safety valve. Keller missed eight games due to injury in 2012 and had a career-low 28 receptions. He should be more affordable after a down season, which is good news for the salary cap-strapped Jets. Safety LaRon Landry made the Pro Bowl last season and is New York's best free agent. But the Jets' defense was fine before Landry and should be fine after. The same can't be said for New York's offense without Keller.