Found this in the SF paper
Chicago -- Though no decision has been made official, Tim Rattay probably won't play tonight against the Bears. The 49ers' usual starting quarterback was held out of the team's brief practice Saturday. Coaches will give him one more look, if he's able to throw before the game.
The oft-injured Rattay hasn't practiced since Monday, when an injury to the forearm of his throwing arm flared up. Because he hasn't practiced, the chances of his playing appear remote.
Ken Dorsey would be making his third NFL start if Rattay is sidelined. Rattay has been fitted for a brace that keeps his thumb from moving, thereby reducing aggravation to his injury. In order to get a grip on the ball, Rattay must wear a glove over the brace. He hasn't practiced much with the contraption, and it's unlikely the team's coaches would take the risk of letting Rattay play without first getting used to the brace. <!-- END STORY -->