The Steelers designated Harmon (foot) for return from injured reserve Wednesday, Ray Fittipaldo of the Pittsburgh Post-Gazette reports.
Harmon said he's 100 percent healthy, but the team will take things day-to-day with the defensive lineman, according to Alan Saunders of SteelersNow.com. Harmon hasn't played since Week 4. He's recorded 12 tackles (three solo), including 1.5 sacks, across 85 defensive snaps this season.