Sullinger, who suffered a stress fracture in his foot in February, was expected to be out for the remainder of the season.
Celtics president of basketball operations Danny Ainge said he was surprised with how quickly the forward recovered from the injury.
“We are excited that Jared’s recovery progressed quicker than initially expected,” Ainge said, according to the team's release. “Jared was extremely diligent in his rehab, repeatedly expressing his eagerness to help our team reach the postseason. He will be available in a limited role this weekend as he works his way back to 100 percent game shape."
The Celtics (34-41) currently have the same record as the Heat, who are also fighting for final the playoff spot in the Eastern Conference. Miami went 3-1 against Boston during the season and own the tiebreaker if both teams were to finish with the same record.
In 51 games before the injury, Sullinger averaged 14.4 points and 8.1 rebounds per game.
- Erick Fernandez