Head coach Mike LaFleur said Monday that Johnson is working through a lower-body injury, Bo Brack of GoPHNX.com reports.
It's unclear when Johnson picked up the injury, though LaFleur relayed that the second-year pro is "progressing well" in his recovery. It doesn't seem like Johnson is in real jeopardy of missing the Cardinals' Week 1 clash against the Chargers. However, his status for the regular-season opener will be more clear once Arizona releases practice participation reports.