"I'd say more than likely," Fox said during his news conference. "Much like earlier things I've said, I don't think all of our issues have been the quarterback. We have confidence in all those guys. But we need to improve, no matter what the position."
Clausen finished 16-of-33 passing Sunday, but he had numerous passes dropped. After managing 6 passing yards and two first downs in the first half, Clausen led Carolina on an eight-play, 75-yard touchdown drive in the third quarter.
Fox deflected much of the blame from Clausen after the game.
"We had a little bit of a spark for about 3½ minutes," Fox said. "In this league, that's not enough."
The Associated Press contributed to this report.