The Maverick has been working out with Izzy, the middleweight champion, and pound-for-pound king Alexander Volkanovski in Puerto Rico this week ... where the two champs have been helping the YouTuber-turned-boxer work on his MMA skills.

By the looks of it, it's been a humbling experience for Logan ... but what do you expect when he's going up against two of the baddest dudes in combat sports?!?

In video of one of the workouts, Logan is on top of Izzy, fighting like hell as Adesanya methodically put him in a Triangle choke, forcing the WWE Superstar to tap.

Logan seemed pretty satisfied with the attempt, though ... saying, "I almost made it out!" with a big smile on his face.

It's been quite the crash course for Paul, who says Israel -- who's more known for his incredibly precise striking than ground game -- has been helping him learn how to kick as well.

Logan -- a decorated high school wrestler -- has expressed interest in MMA in the past ... and his brother, Jake, recently signed with the Professional Fighters League (PFL).