Warren (hamstring) didn't practice Thursday, Teresa Varley of the Steelers' official site reports.
Warren suffered what coach Mike Tomlin referred to as "not a significant" hamstring injury Week 11 against the Bengals, but at this stage the running back's status for Monday night's game against the Colts is uncertain. He now has two more chances to return to practice ahead of the contest, but if he's unavailable, Benny Snell would be in line to log complementary snaps Week 12 behind top back Najee Harris.