NFLPA president JC Tretter says hurdles remain before NFL's return
NFL position battles to watch in joint practices: Dolphins cornerbacks vs. Bucs receivers gets things started
JC Tretter announces his retirement - NBC Sports
JC Tretter Predictions: Will Tretter head to Minnesota to keep Cousins upright?
JC Tretter, former Cleveland Browns center, retires after 8 seasons in NFL but remains NFLPA president - ESPN
Tua Tagovailoa: NFL urged to make 'tangible change' to concussion policy in wake of Miami Dolphins quarterback's head injury, NFL News
JC Tretter: President NFLPA] We do not believe this was a meaningful application of the protocols. Nobody, including the NFL, believes he should have been put back in the game. It is
Why The Miami Dolphins Should Not Sign JC Tretter
Latest On Browns C J.C. Tretter, O-Line Plans
Miami Dolphins QB Tua Tagovailoa out indefinitely after second head injury
Tua Tagovailoa's Head Injury Prompts Changes To NFL Concussion Protocols - WSJ