Mann will start Sunday's contest against the Magic in place of Shai Gilgeous-Alexander (ankle), Joe Mussatto of The Oklahoman reports.
Mann has started 18 of the Thunder's past 21 games due to various injuries among their starting five. As a starter this season, he's averaged 13.2 points, 3.0 rebounds, 2.3 assists and 1.0 steals in 29.8 minutes per game. He figures to see a similar workload against Orlando.