Arizona Cardinals head coach Bruce Arians has revealed that he is "optimistic" about the injury suffered by Calais Campbell on Sunday.

Campbell was carted off during the Cardinals' 32-20 defeat to the San Francisco 49ers at the weekend, having suffered a back injury during a collision with Niners running back Frank Gore.

Team doctors strapped Campbell to a stretcher before taking him to hospital as a precautionary measure, but Arians has said that the fact his defensive end was able to move his fingers and feet as well as talk coherently makes him optimistic that it would not be a serious injury.

"There's been a number of times I've been out there watching guys get towed off on a stretcher, and it's never fun, especially any time it's a head or neck injury involved," Arians told reporters.

"You just start praying and hoping everything is going to be all right, but he was coherent and talking and you could see the fingers and the feet start coming back pretty fast, so I was very optimistic."

Campbell, meanwhile, has expressed his desire to return to action as early as Thursday's match against the Seattle Seahawks.