Johnson is questionable to return to Sunday's contest in San Francisco due to a left knee injury, Kent Somers of the Arizona Republic reports.
Two dominoes fell at the top of the Cardinals' running back depth chart, namely Johnson and Andre Ellington (left foot, questionable), in the third quarter. The departures leave rookie David Johnson to handle the bulk of the carries out of the backfield, though Stepfan Taylor could also factor into RB touches.