Steelers DT Derrick Harmon has a MCL sprain, source (Ian Rapoport) says. He is expected to start the season on the PUP list and miss around a month. via ( rapsheet / X ) #nfl #pittsburgh #steelers #nflplayers #steelernation #nflfootball #nflrookie #defensivetackle #pittsburghsteelers #injuryupdate #steelersnation #steelersnews