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.