Free agent center JC Tretter is retiring from the NFL but plans to maintain his role as NFLPA president.
Tretter, 31, spent eight years in the NFL with the Green Bay Packers and Cleveland Browns, who released him in the offseason due to a knee injury.
"My time on the field may be over, but I'm not stepping away from football," Tretter said in a statement. "I'm looking forward to doubling down on my work as NFLPA Preside