The Buffalo Bills placed linebacker Kawika Mitchell on injured reserve Friday, ending the seven-year veteran's season two days after he hurt his foot in practice.
"Unfortunately Kawika had a lot worse of a problem than we had anticipated," head coach Chan Gailey said. "It was going to be quite a few weeks, and we just couldn't wait."
Gailey added that it was too early to tell if Mitchell would need surgery to repair the problem.
A backup to Andra Davis, Mitchell was coming back from a right knee injury that forced him to miss the final 11 games last season after he went on IR.
Starting outside linebacker Reggie Torbor (chest) and backup linebacker Antonio Coleman (hamstring) are out for Sunday's game, while starting safety Jairus Byrd (groin) will likely play after practicing all week. Byrd is listed as probable on the team's injury report.
Byrd hasn't played in nearly a month after undergoing groin surgery. He earned a Pro Bowl selection as a rookie last year after finishing tied for the NFL lead with nine interceptions.
The Associated Press contributed to this report.