Derek Carr exited the Oakland Raiders' Week 4 loss to the Denver Broncos with back spasms.

Carr left the game with five minutes remaining in the third quarter.

"I think he just got roughed up there. He got tackled. Something causes his back to spasm up," Jack Del Rio said. "I didn't see much that would indicate the he would be injured. His back spasmed up."

After spending some brief time in the medical tent, Carr was ushered into the locker room and did not return to play.

"I tried to come in here and have them work on it. I tried to throw and all those kind of things and it just wasn't ready yet," Carr told reporters after the game. "I tried to do anything I could to be back out there. I just couldn't."