4 former Packers who could come out of retirement and still play in 2023
JC Tretter: Brown center on NFL in coronavirus world
J.C. Tretter hints that role with NFLPA created turmoil with Browns
Former Cleveland Browns C JC Tretter retires
Former Browns center JC Tretter retires after eight seasons
Prominent NFL Veteran Announces His Retirement
Retired center JC Tretter claims Minnesota Vikings 'never returned our call'
JC Tretter: Brown center on NFL in coronavirus world
Former Browns center, NFLPA president JC Tretter retires –
Free agent JC Tretter retires, will focus on NFLPA role - National Football Post
J.C. Tretter, former Browns center and NFLPA president, retires from NFL - The Athletic
Former Browns center JC Tretter retires, will stay on as NFLPA president
Browns center JC Tretter and Seahawks linebacker Shaquem Griffin announce retirement
Browns center Ethan Pocic's business-like approach pleases team