Warren, Witherspoon out vs. Colts, Boykin and Spillane questionable

Jaylen Warren emerged as the legitimate No. 2 back the Steelers have needed for a long time. However, they won't have him in the lineup this week.

Warren and Ahkello Witherspoon, both nursing hamstring injuries, have been ruled out for the Steelers' Monday Night matchup with the Colts.

Warren suffered his injury in the first quarter of the Week 11 loss to the Bengals while Witherspoon has only played one game since initially injuring his hamstring in Week 3.

While Najee Harris has been the driving force of the Steelers' improved running attack over the past two weeks, Warren's increased role in the offense has allowed Harris to stay fresh and be more efficient in the snaps he's been given.…