Williams left Friday's matchup with the Redskins due to a rib injury, Vic Carucci of WGRZ-TV repots.
Williams had recorded 42 yards and one touchdown on 11 carries prior to being forced out of the game. He currently projects as the fourth running back on the team's depth chart, so he is competing for a spot on the final roster. The severity of the injury is not known at this time.