IRVING, Texas — Cowboys rookie linebacker Brandon Williams has a torn knee ligament and is likely headed for season-ending surgery.

Coach Wade Phillips said Saturday that Williams "played very well on special teams. We lost an outside linebacker that we were hoping would help us some this year."

A fourth-round pick from Texas Tech, Williams was injured while trying to make a tackle on a punt return in Dallas' 30-10 victory over Tennessee on Friday night. Victor Butler will replace Williams as the primary backup on the strong side.

Steve Octavien also is likely to move up in the rotation.

Also, third-string quarterback Stephen McGee sprained a knee while throwing a late touchdown pass and may miss about a week. Inside linebacker Justin Rogers aggravated a knee problem and may miss a week as well.