Risner (back) has been ruled out ahead of Sunday's game against the Lions, Alec Lewis of The Athletic reports.
Risner started the season on injured reserve due to a back injury, but his 21-day practice window opened Monday. He was a limited participant in all three practices this week, and although he won't return Sunday, he could be activated off IR ahead of the Vikings' Week 8 clash against the Rams on Thursday Night Football.