Harmon (foot) has been ruled out from returning to Thursday's clash versus Cleveland, Nick Farabaugh of PennLive.com reports.
Harmon was carted to the locker room during the first half after suffering a foot injury. He returned to the field with Pittsburgh after halftime but then went to the locker room with a trainer and was subsequently ruled out. Yahya Black is slated for more work on defense in Harmon's stead.