Floyd Mayweather's fight with Tenshin Nasukawa is a complete joke and is nothing but a money grab ... so says Bob Arum, who RIPPED Floyd for even taking the fight.
"It is a non-event. It is not a sporting event," Bob tells TMZ Sports.
Arum was out at Craig's this week when he made sure to stop for our photog, to crap all over Mayweather's highly-anticipated New Year's Eve exhibition in Japan.
"That's pretty much a joke, isn't it? I think so. I think so. Because, it's not a real fight ... the people who are watching that nonsense are pretty well jerks."
In fact ... Bob tells us he thinks the ONLY reason the tilt is going down is 'cause Mayweather straight-up NEEDS the cash!!
"He needs money for Christmas and the New Year, and this is a good way for him to make some money. God knows Floyd always needs money!"
We also asked Bob about the Oscar De La Hoya-Dana White feud ... and he tells us why it's "stupid" -- and, then says, even at 87 years old he could kick the crap outta Dana!!!