Floyd Mayweather -- I'm Gonna Train Michael Jackson's Son ... To Fight!

Michael Jackson's son could be the next great boxing prodigy -- because Floyd Mayweather says he is going to PERSONALLY train Prince Jackson ... now that he's apparently joined The Money Team.

Floyd was PUMPED when he saw the pics of Prince rollin' around Calabasas this weekend in a truck covered in "The Money Team" decals -- and yesterday, Mayweather told us he can't wait to train the kid.

"I haven't worked with him yet, but I look forward to working with him when I get back to Las Vegas," Mayweather told TMZ Sports.

But Prince's uncle Jermaine Jackson says all is not as it appears ... telling TMZ Sports his nephew is NOT an official TMT member and only got into the TMT vehicle because he likes big trucks.

Doesn't seem to matter to Floyd ... at this point, seems Prince is officially in the crew ... whether Jermaine likes it or not.