The Heat lead the series, 2-1, with Game 4 of the Eastern Conference Finals slated for Monday night in Boston.
Butler was forced to exit for the final 24 minutes of Game 3 after suffering from right knee inflammation. The Heat still held on for a 109-103 road win.
Haynes reported there’s a “strong possibility” that Butler won’t miss the next game. Butler is averaging nearly 29 points during the playoffs.