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?

Houston Texans: Free safety Glover Quin. A converted corner, he’s a solid and reliable player. Like all the guys in the secondary besides corner Kareem Jackson, Quin was not as good in 2012 as he was in 2011. But he’d be difficult to replace, and there is a nice continuity there.

Indianapolis Colts: Punter Pat McAfee. He’s the league's third-ranked punter according to Pro Football Focus, and outside of quality punting, he’s a strong kickoff guy who can line up for a field goal in an emergency. There are not a lot of other guys heading toward contractual freedom. Darius Butler played some good cornerback but didn’t do well staying healthy.

Jacksonville Jaguars: Cornerback Derek Cox. When he plays, he’s quite good. The problem is he gets hurt a lot, and the team has consistently needed to find alternatives to him because he has been unavailable. It’s hard to gauge his value, but let him leave and the talent pool at corner is awfully thin for Gus Bradley’s first defense in Jacksonville.

Tennessee Titans: Tight end Jared Cook. Cook was miserable last season with Chris Palmer as offensive coordinator. He bemoaned Mike Munchak’s decision to part ways with John Zernhelt as tight ends coach, but the last time George Henshaw coached the position for the Titans, players such as Frank Wycheck and Jackie Harris were quite productive.