Johnston (groin) is listed as questionable for Sunday's game at Dallas.
Johnston sat out this past Sunday's win at Kansas City after he showed up on the Chargers' final Week 15 injury report as limited due to a groin issue. He then had practice restrictions this week before the team tagged him with a designation for Week 16 action. His status ultimately will be confirmed about 90 minutes before Sunday's 1:00 p.m. ET kickoff, but Tre' Harris would figure to benefit again if Johnston is inhibited or sidelined this weekend.