2011 Free Agency: Star rating is out of five. Age listing as of Sept. 1, 2011.
Ryan Kalil, C, Panthers. Age: 25. Franchised by Panthers
If the Panthers don't franchise Ryan Kalil, teams will be lining up to sign one of the top centers in the NFL.
Olin Kreutz, C, Bears. Age: 34. Signed with Saints (1 year)
It's not saying much, but Olin Kreutz was Chicago's best pass-protector in 2010. He's a declining player at this stage of his career, but he just doesn't miss any games; Kreutz made his 129th consecutive start in the season finale.
Lyle Sendlein, C, Cardinals. Age: 27. Re-signed with Cardinals
Arizona's best offensive lineman, Lyle Sendlein hasn't missed a start in three years. He needs to be re-signed.
Kyle Cook (RFA), C, Bengals. Age: 28.
Kyle Cook has been a solid, dependable starting center for the Bengals the past two years. He deserves an extension.
Jonathan Goodwin, C, Saints. Age: 32. Signed with 49ers (3 years, $10.9 million)
A serviceable starting center, Jonathan Goodwin still has a couple of quality seasons left in the tank.
Chris Spencer, C, Seahawks. Age: 29. Signed with Bears (2 years)
The injury-prone Chris Spencer had a rocky start to his 2010 campaign, but improved toward the end of the season.
Samson Satele, C, Raiders. Age: 26. Re-signed with Raiders
Samson Satele has done a decent job as Oakland's starting center the past two years after struggling in Miami.
Scott Mruczkowski, C, Chargers. Age: 29. Re-signed with Chargers
Scott Mruczkowski barely played this season, but filled in really well for an injured Nick Hardwick the year before.
Rasul Douglas is an interesting pick for the Eagles. He was a ballhawk last year with eight interceptions, to tie for the lead in the nation. He is a big press man corner. He has issues in zone and off man, but Douglas could develop into a starter.