Trae Young Defends Devin Booker's Pickup Game Tantrum, No Double-Teaming!

Trae Young is going to bat for his NBA buddy, Devin Booker ... saying the dude had every right to throw a tantrum in a pickup game Monday -- adding it's insane people were double-teaming him!!!

"DBook speaking facts," Trae said of the Phoenix Suns superstar Wednesday ... "There should be NO Double Teaming in pick up."

Of course, Booker went off on some guys in an open-run sesh earlier this week when he was doubled on the baseline while trying to attack the basket.

"Hey, bro, we not doubling in open gym, bro!" Booker yelled.

Devin caught a ton of heat for the blowup, with people claiming he was being a baby ... but Trae came to his defense on Twitter, saying Booker SHOULDA been pissed.

"When you trying to work on your game, and work on the moves and things you do individually in pick up... it’s annoying getting double teamed in that type of setting."

Trae added, "Just Sayin.. #OnlyAFewUnderstand"

For his part, Booker clearly appreciated the backing ... writing, "Only a few."