Reid said quarterback Michael Vick will run the offense in practice Wednesday and Thursday and "we'll take Friday as it comes."
Reid had said Monday that both Kolb and Bradley would not practice before Friday. However, Reid did not rule out either player for Sunday's game at Detroit.
Bradley sustained a concussion when he collided with Ernie Sims during Philadelphia's 27-20 loss to Green Bay on Sunday. Yet somehow, the Eagles' middle linebacker returned for a few plays before he was pulled for the rest of the game.
Minutes before Bradley went down, Kolb's head was slammed down so hard on a tackle from behind that a chunk of grass got stuck in his helmet. He got up slowly and walked off the field.
The team initially said Kolb had a jaw injury, and the quarterback returned to throw three passes before sitting out the rest of the game with a concussion.
Head injuries were an important issue for the NFL in the offseason. Last year, the league implemented stricter return-to-play guidelines for players who show concussion symptoms, and each team must consult with an independent neurologist whenever there is a head injury.
Information from The Associated Press was used in this report.