Notes: Phil Dawson retires after 21 seasons, will sign contract to do so as member of Browns - BrownsZone with Scott Petrak
Former Browns center JC Tretter announces retirement from NFL
Former Cleveland Browns Center J.C. Tretter has retired - Bucs Life
Former Browns center JC Tretter announces retirement from NFL
Former Browns center, NFLPA president JC Tretter retires National News - Bally Sports
JC Tretter Retires From NFL After Nine-Year Career - Sports Illustrated
Report: 49ers C Alex Mack to retire after 13-year NFL career - Niners Nation
Former Browns center J.C. Tretter hangs 'em up, we think
JC Tretter, former Cleveland Browns center, retires after 8 seasons in NFL but remains NFLPA president - ESPN
JC Tretter Retires from NFL at 31; Former Packers, Browns Center Is NFLPA President, News, Scores, Highlights, Stats, and Rumors
JC Tretter's busy offseason centers on helping new teammates, players around NFL acclimate to unique circumstances
JC Tretter Retires From NFL After Nine-Year Career - Sports Illustrated
49ers news: CBS' Sports believes the 49ers should sign C J.C. Tretter before the season starts - Niners Nation