It's the same knee on which Bush had surgery last December to repair cartilage.
Bush is coming off one of his best games of the season, when he gained 98 yards and scored two touchdowns last Sunday in St. Louis.
Payton said he hopes Bush can practice Friday, but that the team will be cautious about doing anything that could set back the fourth-year pro.
Bush wasn't available for comment.
Copyright 2009 by The Associated Press