Top free agent offensive guards/centers: Alex Mack
This two-time Pro Bowler has been one of the NFL's top 10 centers since the 2009 season according to ProFootballfocus.com. Last season, Mack allowed two sacks and 18 hurries and committed just three penalties. This 28-year-old, who has started every game in his five seasons with the Browns, will be an asset to any team looking to upgrade their offensive line. Mack did recently receive the transition tag, so any team making him an offer would have to include a poison pill to dissuade the Browns from matching.