Warren (knee) has been ruled out for Sunday's game against the Colts, Teresa Varley of the Steelers' official site reports.
Warren, who didn't practice this week, thus will target a potential return to action Sunday, Oct. 6 against the Cowboys. In Warren's looming absence, look for Cordarrelle Patterson to see added complementary looks behind top back Najee Harris, with Jonathan Ward and/or Aaron Shampklin candidates to be elevated from the practice squad ahead of Week 4 action.