Just past the halfway mark of the game, Oshie gained control of the puck behind the net in the offensive zone. He skated along the boards to near the half-wall, where he was hit up high by Wild forward Mike Rupp.
Oshie laid face-first on the ice for several moments before trying to get to his feet. He fell on his first try but was able to get off the ice and down the tunnel to the locker room on his own.
Rupp, playing his first game since Feb. 1, was assessed a match penalty at 10:30.
"Like everything else at this time of the year, he's day-to-day," coach Ken Hitchcock told the Blues website. "But certainly tough hit to take right now."
The Blues lost 4-2.
Oshie entered Thursday tied for the Blues lead with 60 points (Alexander Steen).