LAKE FOREST, Ill. (AP) - Chicago Bears quarterback Jay Cutler missed practice on Thursday and his playing status remains in question because of a concussion.

Coach Lovie Smith says Cutler continues to improve, but it's not clear if he'll be ready to play at San Francisco on Monday night.

If Cutler can't play, Jason Campbell will likely make the start.

The Bears believe Cutler was injured on a helmet-to-helmet hit from Houston's Tim Dobbins late in the second quarter of Sunday's loss. He finished the half, but missed the second half after showing symptoms in the locker room.

Cutler needs to be cleared by team physicians and independent neurological consultants before he can return.

The same goes for teammate Shea McClellin and 49ers quarterback Alex Smith, who also suffered concussions last week.