Udonis Haslem Threatens To Beat Jimmy Butler's 'Ass' During Heated Team Huddle

Udonis Haslem was so frustrated with his teammate Jimmy Butler during Wednesday night's game ... he threatened to beat the star's "ass" in a team huddle.

The chaotic scene went down during Miami's home game against the Warriors at FTX Arena ... when "Jimmy Buckets" and UD almost came to blows during a timeout.

Haslem and Butler, who had been sitting down, were arguing ... when Udonis appeared to yell, "I'm not your f***ing kid," which prompted Jimmy to stand up from his seat.

Haslem then began shouting, "I'll beat your ass!" while looking Butler dead in the face.

In a video of the heated interaction, filmed by someone sitting courtside, you can see UD repeatedly saying he'd beat up Jimmy ... and even taking steps toward the Heat guard as his teammates were restraining him.

Heat coach Erik Spoelstra found himself in the middle of the scrum ... and even he appeared to have words for Butler during the altercation as well.

The blowup ultimately led to a loss for Miami ... and afterward, Spoelstra tried to play it all off.

"Everybody was wondering where the dinner plans were after the game," Spoelstra said.