ST. LOUIS (AP) — The Steelers will wait for results of an MRI on Ben Roethlisberger’s left knee after the three-time Pro Bowl quarterback was carted off the field in the third quarter of Sunday’s 12-6 win at St. Louis.

Michael Vick replaced Roethlisberger, who got hurt when his leg was caught underneath him on a diving, sliding sack by Mark Barron. Big Ben left the stadium on crutches and wearing a bulky brace.

Steelers coach Mike Tomlin said he won’t have an update on the extent of Roethlisberger’s injury before Monday.

“I was kind of stunned,” Vick said. “You never want to see a guy like Ben go down.”

Roethlisberger hasn’t missed a start since 2012, when he was out for three games late in the season because of a shoulder injury. Vick completed 5 of 6 passes for 38 yards in relief.

The Steelers (2-1) host the Baltimore Ravens (0-3) on Thursday night.

Later in the day, Seattle running back Marshawn Lynch left a 26-0 win over Chicago at halftime with a hamstring injury. Lynch finished with 14 yards on five carries and spent half of the first quarter in the locker room before coming to the Seahawks bench. Lynch was questionable entering the game with a calf injury.

“We’ve checked it all out and it’s nothing to be alarmed by,” Seahawks coach Pete Carroll said.