Steelers RB Cordarrelle Patterson ruled out with ankle injury

INDIANAPOLIS -- Already down a running back, the Pittsburgh Steelers offense took another blow as RB Cordarrelle Patterson was ruled out with an ankle injury sustained in the second quarter of the Steelers' game Sunday against the Indianapolis Colts.

The Steelers trailed the Colts 17-3 at halftime.

Patterson was injured on the Steelers' best drive of the afternoon as he picked up a first down in the red zone on a 10-yard gain. A play later, though, wide receiver George Pickens fumbled as he was tackled near the goal line and the Steelers turned the ball over.

Patterson picked up four first downs on that drive and left the game averaging 7.2 yards per carry with 43 yards on six attempts. He also had two catches on two targets for 19 yards.

Without Patterson, the Steelers went back to Najee Harris and added practice squad running back Aaron Shampklin to the mix.

Harris, though, has been ineffective, with 8 yards on eight carries early in the third quarter. Shampklin got one carry before halftime for a 5-yard gain.