The Blues lead 1-0 in the best-of-7 series against the Chicago Blackhawks,
Oshie missed Game 1 on Thursday and the last two games of the regular season after getting hit in the head by Minnesota Wild forward Mike Rupp on April 10. Rupp was suspended four games for an illegal check to the head.
Oshie started the game on the Blues first line with David Backes and Alexander Steen. Steve Ott played in that spot in Game 1 and assisted on Steen's triple-overtime winning goal, but he was moved to the third line with Derek Roy and Ryan Reaves.
Oshie's return also pushed Brenden Morrow out of the lineup, but it's not clear if Morrow is a healthy scratch or if it is because of an injury. He did not play the last three games of the regular season because of an injury.
Blues forward Patrik Berglund is missing his third straight game with an upper-body injury.
The Blackhawks are using the same lineup for Game 2 as they used in Game 1.
Here are the lineups based on pregame warm-ups:
Injured: Patrik Berglund (upper body)