Clippers stud Montrezl Harrell took policing loud-mouth fans into his own hands again Monday ... telling a courtside heckler to "shut the f*ck up, now!"
It all went down at the L.A.-Timberwolves game in Minnesota ... when Harrell's Clips were getting ribbed by some guy with floor seats at the free-throw line.
Montrezl wasn't in the mood to hear it ... and turned to the dude and screamed, "Be a fan, bro. Sit over there and be a fan. Shut the f*ck up, now!"
It ain't the first time Harrell's gone after a heckler ... back in December, he threatened to "smack the sh*t out" of some guy who was chirping at him on the way to the locker room.
Montrezl Harrell was ready to smack the shit out of Chad @MickstapeShow pic.twitter.com/Ic0It8ZYfS
Of course, Harrell's one of MANY who have had incidents with fans this season ... guys like Kevin Durant and Blake Griffin have hit back hard at smack-talking guys in the stands.
Doesn't seem the clapbacks are ending anytime soon ... but if anybody wants to learn how to calmly deal with the situation -- don't forget Julius Randle's advice!!!