Steelers linebacker Nick Herbig could barely walk when he left Sunday Night Football in the third quarter.
He limped to the sideline medical tent and then limped from there to the X-ray room.
The Steelers list him as questionable to return with a hamstring injury.
Herbig has two tackles, half a sack and a fumble recovery.
The Steelers lead the Cowboys 10-6 heading into the fourth quarter with Dallas going 0-for-3 in the red zone and ending another drive at the Pittsburgh 20 without any points. Dak Prescott lost a fumble on a shared sack between Herbig and T.J. Watt, with Watt forcing the fumble and Herbig recovering it; Prescott threw an interception to Donte Jackson in the end zone; and Brandon Aubrey had a 38-yard field goal blocked by Isaiahh Loudermilk on a drive that ended at the Pittsburgh 20.
The Cowboys have three red zone points.