TORONTO — Mickael Pietrus wanted to return to the Celtics, hoping that offseason right knee surgery that improved his flexibility and athleticism would convince the club to bring him back. It didn’t.

Pietrus, who was a key player off the bench in the Celtics’ run to Game 7 of the Eastern Conference finals, signed with the Raptors in late November and was a steady contributor until being replaced in the rotation by rookie Terrence Ross. Entering Wednesday night’s game against Boston, Pietrus hasn’t played since Jan. 9 because of left knee soreness and the decisions of coach Dwane Casey.