CM Punk ain't lettin' his 2 UFC ass-whoopings stop him from training to fight ... 'cause his teammate and UFC star, Anthony Pettis, says Punk is STILL hitting the gym hard.
TMZ Sports talked to Pettis -- the former UFC lightweight champ who's moving up to welterweight to fight #2-ranked Stephen "Wonderboy" Thompson on Saturday at Fight Night 148 -- about his Roufusport gym mate's fighting future.
"He is still training. I don't know what his plan is. I know he's doing some movies and a couple other things, but I'm not sure if he plans on fighting again or what. But, I know he's still training ... That dude's a hard worker."
Remember, Punk was dominated and choked out by Mickey Gall in September 2016 ... before returning to face Mike "The Truth" Jackson.
Punk lost to Jackson via a unanimous decision ... but looked like a much-improved fighter.
Pettis says he respects the hell outta CM Punk ... even with an 0-2 record.
"Not many people in the world can do what he did. I mean, it's on the biggest stage, and he fought some good guys too. It's not like he was fighting scrubs. He's fighting good guys in the UFC."
"He's training with killers. He's training with me, Woodley. He comes in day and day, and he's getting his butt kicked, and coming back, showing up, so I give him props, man. No matter what, he did it."
We also talked to Wonderboy -- who hasn't fought in 10 months after sustaining an injury fighting Darren Till -- about exactly how he plans to become champ by the end of 2019.