Johnson, who was placed on the active/PUP list Thursday, is managing a knee injury that isn't considered serious, Darren Urban of the Cardinals' official site reports.
Johnson finished last season on IR due to an MCL injury, and he's not quite ready to participate in training camp. However, coach Mike LaFleur said that the offensive lineman's placement on the PUP list was "really just maintenance" and indicated that Johnson will "be back before you know it." It sounds like Johnson is expected to be good to go by the beginning of the regular season, and he's slated to be Arizona's starting left tackle.