Mitchell, 21, went down in the third quarter but later returned to the game. Shams Charania of Yahoo Sports reported X-rays came back negative. After the game, Jazz coach Quin Snyder said Mitchell is experiencing some soreness, according to Royce Young of ESPN.com.
Mitchell had an MRI on his left foot that came back negative as well, according to ESPN's Chris Haynes, who added he's going to play in Game 2 Wednesday.
Mitchell finished with 27 points and 10 rebounds in his playoff debut, a 116-108 Thunder win.
Selected with the No. 13 overall pick in June's draft, Mitchell has broken out as a Rookie of the Year contender. He led the Jazz and all rookies with 20.5 points per game, becoming the first rookie since Carmelo Anthony to lead a playoff team in scoring.
"The kid inside me has really enjoyed it," Mitchell told reporters. "I got the Defensive Player of the Year and Coach of the Year on my team and we're the No. 5 seed and nobody thought we'd even be in the playoffs. So I'm excited to get this thing going."
Mitchell played well in his first playoff game, but the Jazz will be hopeful he feels fine after the contest. Utah's scoring is already not a strong suit, and Mitchell is often the engine that keeps its offense afloat.