The Steelers placed DLE Aaron Smith on injured reserve Wednesday after the 11th-year veteran suffered a significant right shoulder injury in the Week Five victory over the Lions.

To fill Smith's spot on the roster, the Steelers signed DL Ra'Shon "Sonny" Harris from the Panthers' practice squad.  Harris was a sixth-round pick by Pittsburgh in the 2009 draft before getting cut late in the preseason and being claimed on waivers by Carolina.

Smith, 33, notched nine tackles and two sacks this season. He has been one of the anchors of the Pittsburgh defense throughout this decade. Strong at the point of attack, Smith is one of the NFL's better ends playing the run, and his loss is a big blow to the defending champs' "D."