McKinnon missed Thursday's preseason game and practice earlier this week with an undisclosed injury, the Minneapolis Star Tribune reports.
It's likely a minor ailment and he wouldn't have played in the final preseason game even if healthy, but it's something to monitor ahead of Week 1. McKinnon had a strong preseason and there's been talk of him being used more this season as a third-down back. However, we won't get a full read on his usage once he plays with Adrian Peterson, as Peterson did not play in the preseason as the Vikings played it safe with their franchise star.