Cardinals quarterback Carson Palmer is believed to have a torn ACL, according to NFL.com.

Palmer left the game late after going down on a passing play. Palmer's shoulder was glanced on the play, but it looked like he injured his leg when he planted. After he walked off the field, Palmer was carted to the locker room. The Cardinals announced Palmer had a left knee injury, and he was deemed questionable to return to the contest. Palmer did not return, and will have more tests to determine the severity of the injury.