Thielen (hamstring) isn't participating in Thursday's practice, Courtney Cronin of ESPN.com reports.
Given that Thielen wasn't even on the field for Wednesday's light walk-through session, it comes as little surprise that he was confined to working out on a side field during a more intense practice Thursday. The Vikings haven't officially ruled Thielen out for Sunday's game against the Lions, but his inability to practice on even a limited basis at this stage of the week suggests he's likely in line to miss a fourth consecutive contest.