Michigan senior cornerback Troy Woolfolk left the game in the second quarter of the Wolverines' season opener against Western Michigan with a sprained left ankle.
After being looked at on the sidelines by trainers, he was carted up the Michigan Stadium tunnel. After halftime, Woolfolk limped out of the locker room after the rest of his teammates, accompanied by a trainer. He was still dressed in uniform and went through backpedals to test the injury.
Michigan head coach Brady Hoke said Woolfolk was held out for precautionary reasons but could have returned.
Woolfolk missed all of the 2010 season after injuring his other ankle in the preseason. He was replaced by senior cornerback J.T. Floyd.
Woolfolk is the second defensive starter Michigan lost Saturday. Before the game, redshirt sophomore linebacker Cam Gordon was ruled out of the game when his back flared up. He did not dress.
Michigan said starting offensive guard Ricky Barnum, backup running back Stephen Hopkins and reserve linebacker Marell Evans were suspended for Saturday's game because of a team matter.
Michael Rothstein covers Michigan for WolverineNation.