Thielen (hamstring) wasn't taking part in the portion of Wednesday's practice open to the media, Courtney Cronin of ESPN.com reports.
Although Thielen stretched before the session, he didn't have a helmet once drills kicked off. Because coach Mike Zimmer considers Thielen "week-to-week," he can't be ruled out for Sunday's contest against the Broncos just yet. Ultimately, the Vikings may wait to make a decision on Thielen until game day, especially if he's able to take the practice field by week's end.