Phillips didn't play against TCU on Oct. 5 or on Saturday against Texas due to his back condition. He started the first four games and had been a pleasant surprise for the Sooners, recording seven tackles, including two for loss, and one sack. Redshirt freshman Jordan Wade started against TCU and Texas in Phillips' absence.
Senior linebacker Corey Nelson, who tore a pectoral muscle in the win over Texas Christian, also had season-ending surgery on Tuesday, Stoops said. Nelson had delayed the surgery so that he could travel with the team to Dallas for the Red River Rivalry game.