Jake Paul Has No Chance In Nate Diaz MMA Fight, Says Rafael dos Anjos

Jake Paul can train nonstop for the rest of his life, but there's no way he'll come close to beating Nate Diaz in an MMA fight -- so says former UFC champ Rafael dos Anjos, who tells TMZ Sports The Problem Child will NEVER beat the MMA legend in his own sport!

We caught up with RDA ahead of his big matchup against Vicente Luque at UFC Fight Night on Saturday ... and considering dos Anjos once beat Nate in the Octagon, we had to ask about Jake calling out Diaz for a rematch in the PFL SmartCage.

Of course, Jake previously said on Logan's "Impaulsive" podcast he'd be able to handle Nate in an MMA fight if he had eight or nine months of training under his belt.

But dos Anjos thinks Jake needs to be brought back down to earth.

"Nate is a fighter," dos Anjos said. "He got good jiu-jitsu, he has that mentality, the fighter mentality. It's a real fight. When you go to the ground and elbows and knees -- it's a different game."

"I think Jake Paul can train as much as he wants, he don't beat Nate Diaz in an MMA fight."

As for his fight with Luque, RDA said he's expecting a war ... and doesn't see it being left up to the judges.

We also spoke with Luque about the matchup ... and he said it's an honor to go up against dos Anjos because he's a bona fide legend in the sport.