Ben Roethlisberger to undergo MRI on knee; left stadium on crutches

Pittsburgh Steelers quarterback Ben Roethlisberger will undergo an MRI to determine the seriousness of the left knee injury he suffered during Sunday's win over the St. Louis Rams.

Head coach Mike Tomlin confirmed the news Sunday, saying simply that Roethlisberger "has a knee and is getting an MRI."

Roethlisberger was taken to the locker room on a cart and was ruled out for the rest of the game in the third quarter. Following the game, the Pro Bowl quarterback was seen walking with crutches.

Veteran Michael Vick, signed in the offseason, replaced Roethlisberger at quarterback and would likely be the Steelers' starter going forward, with Landry Jones backing him up.

Roethlisberger immediately grabbed at his knee area after going down on the play. He appeared to be in considerable pain before being helped off the field.