The news made it back to LaVar ... and of course he didn't back down, offering to end the speculation with a 2-on-2 game, Shaq and Shareef, vs. LaVar and LaMelo.
Well, Shaq -- wearing a hilarious white wig -- made a video message to respond to LaVar, and he's in ... saying if his fam loses, he'll glue the white wig to his head for good.
Challenge accepted. Is the T-Mobile Arena available?!