CM Punk is open to returning to wrestling someday -- just not with the WWE.

The "Best in the World" left the squared circle for the Octagon, but, though he's not completely enamored with the idea, he said he isn't opposed to returning to his roots down the line. He also made it very clear that he'll never set foot inside a WWE ring again.

Punk, 37, walked out on the WWE back in January 2014 and signed with the UFC that December, but he's suffered myriad setbacks when training for his debut. His first fight is finally official, as he'll take on 24-year-old Mickey Gall at UFC 203 on Sept. 10 in Cleveland.

What happens after that fight is anyone's guess, but the former WWE World Heavyweight Champion was at first dismissive of a return to the ring, then said he might someday.

"No, I don't think so. But it is one of those 'never say never' things," Punk told ESPN about a wrestling return. "I like to cover all my bases, just so some internet dweeb is going to be like, 'you said you'd never wrestle again!' But WWE? No. Absolutely not. But you never know, I could pop up here and there.

"Let me explain that to you even better... it's not going to even be televised, it's going to be me in a ninja f--king outfit wrestling one of my buddies and nobody's ever going to know. It's going to be very 'Monty Python' so to speak.

It's quite clear Punk still has some bad blood toward the WWE.

He walked out on the company for many reasons, which include his frustration over how he was being used and for constantly having to work hurt. He opened up about his departure on his friend Colt Cabana's podcast and was subsequently sued for defamation for making disparaging remarks about WWE Dr. Chris Amann.

Punk's wife, former WWE Diva AJ Lee, then eventually left the company after the lawsuit came to light.

For now, Punk is looking ahead to Gall, who has plenty of confidence taking on the debuting UFC star in September. After that? He could end up anywhere ... just not in WWE.

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