DAVIE, Fla. (AP) -- Reggie Bush has joined the Miami Dolphins injury list with a sore knee. The team's leading rusher was added to the injury report after being limited in practice Thursday. Bush hurt his left knee Sept. 23 against the New York Jets but has started every game. The Dolphins (2-3) are already thin at running back going into Sunday's game against St. Louis (3-2). Backup Daniel Thomas sat out practice for the second day in a row after suffering a concussion for the second time this season last Sunday. Cornerback Richard Marshall remained sidelined with a back injury. He missed Sunday's win at Cincinnati.