Pittsburgh activated Riley (ankle) from injured reserve Friday, and he has no injury designation ahead of Saturday's contest against the Bengals, Teresa Varley of the Steelers' official site reports.
Riley sat out for the four-game IR minimum after sustaining an ankle injury in Week 11 against the Browns. He's primarily played on special teams but could see defensive snaps with Minkah Fitzpatrick (knee) and Trenton Thompson (neck) both ruled out for Sunday's game.