NFL sources are reporting that St. Louis Rams quarterback Sam Bradford is out for the season after an MRI on Sunday night showed he tore the ACL in his left knee, which happened late in the game at Carolina.

Bradford got hurt with 5:27 to play. Carolina safety Mike Mitchell made contact with Bradford before he stepped out of bounds, but Bradford fell on his knee as he hit the ground.

Bradford was on crutches and in an ankle-to-thigh brace as he left the locker room. After the game, head coach Jeff Fisher didn’t want to speculate on the injury.

“I’m not going to deal with hypotheticals right now until I find out what really is going on with him,” Fisher said.

Kellen Clemens is Bradford’s backup and went 2 of 4 for 19 yards. Clemens is the only backup quarterback on the Rams’ roster or practice squad.