Jimmy Butler very well may have played his last game for the Miami Heat -- the team just suspended the superstar again ... but this time, there's no timetable for his return amid the ugly feud.
The news broke on Monday ... with Shams Charania saying the six-time All-Star walked out of the team's shootaround after learning he was losing his starting role to Haywood Highsmith.
It marks the third time this month Butler's been hit with a punishment -- he was suspended for seven games back on Jan.