The Steelers signed Spence to a contract Wednesday, Teresa Varley of the Steelers' official site reports.
With Ryan Shazier dealing with severe spinal injury and unlikely to play Sunday against the Ravens, the Steelers will bring back Spence, who suited up for 31 regular-season contests with Pittsburgh between 2014 and 2015, to provide some insurance at the second level. Spence played exclusively on special teams in his lone three appearances with the Colts earlier this season, but his familiarity with Pittsburgh's schemes could offer him a better chance at logging defensive snaps in his second stop of 2017.