Husker senior running back Rex Burkhead sat out practice for the second consecutive day, raising doubts about whether or not he will be ready to play when Nebraska hosts Michigan on Saturday. Burkhead re-aggravated his left knee injury in Saturday’s win over Northwestern. The Huskers have gotten some good injury news elsewhere. Cornerback Josh Mitchell, who missed Saturday’s game with an ankle injury, is expect to play against Michigan, as is defensive tackle Kevin Williams. Defensive tackle Chase Rome is also hoping to return, but he first must be cleared after he suffered a concussion. The returns of Williams and Rome would help shore up a defensive tackle rotation that was frighteningly thin last week. The team has already lost true freshman tackle Avery Moss for the season with a shoulder injury.