Hainsey put no weight on his leg as he left the field and used crutches to get to the locker room. Starting right guard Josh Lugg moved into Hainsey's role after the injury.
A team captain, Hainsey started his 22nd consecutive game on Saturday. Notre Dame is already without another starting lineman, Tommy Kraemer, for four to six weeks because of a knee sprain.
The Irish next play Nov. 9 at Duke.