Theo Riddick out with head injury

GREEN BAY, Wis. -- Detroit Lions running back Theo Riddick, who suffered a head injury, will not return to Sunday's game against the Green Bay Packers.

Riddick walked off the field in the first half following a kick return with the help of trainers and did not return to the field.

Riddick usually is a special teamer, including the player tabbed to handle short kick returns with Micheal Spurlock deep. He also has a small role in the offense, usually playing a handful of snaps.