Ohio State quarterback Braxton Miller left Saturday's game against San Diego State with a sprained MCL on the opening drive of the game, according to ESPN.
He is out for the remainder of the game.
Miller was injured after being pinned between tacklers.
Miller, a junior and Heisman Trophy candidate, carried the ball on fourth-and-1 at the Aztecs' 12-yard line. After cutting inside, he was hit by defensive back King Holder and middle linebacker Jake Fely. Miller's helmet came off as he hit the ground.
After lying on the ground while being examined by trainers, he was helped up and walked to the sideline on his own before getting carted off to the locker room. His left knee was put it in a brace.
Kenny Guiton took over for Miller and the Buckeyes took a 7-0 lead on the next play when freshman Dontre Wilson scored on a 7-yard run.
Guiton also threw a touchdown pass and ran for a 44-yard score.
Ohio State led San Diego State 35-0 at the half.