Johnson didn't practice Thursday due to a rib injury, Darin Gantt of the Panthers' official site reports.
Johnson was listed as a non-participant Wednesday for non-injury-related/rest reasons in addition to the rib issue, but the Panthers' latest practice reports attributes his absence Thursday only to the injury. He'll still have another chance to log some practice reps before the Panthers potentially make a decision on his availability for Sunday's game at Denver. For his part, Johnson said after Thursday's practice that he believes he'll be ready to play this weekend, per David Newton of ESPN.com reports.