Paul Heyman didn't exactly sound confident in CM Punk's transition from the squared circle to the Octagon, calling the attempt "improbable" and citing the former WWE Superstar's lack of experience.

Heyman managed Punk during his WWE career and they keep in touch to this day despite the "Best in the World" leaving the organization in January 2014. After the company officially cut ties with him in June of that year, the former WWE Champion signed with UFC that December.

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Punk, whose real name is Phil Brooks, has trained out of Roufusport in Milwaukee for his debut, which has been pushed back several times and still remains a mystery. Heyman believes Punk's age and lack of experience could hurt him, but admitted it was a noble attempt for the former wrestler to pursue his MMA dreams.

"Phil Brooks is not in his mid-thirties, he's cruising rapidly into his late-thirties," Heyman, who now manages former UFC champion Brock Lesnar, said on the SI Media Podcast, according to Fox News. "He doesn't have a documentable athletic background. Do I know that he has been in the gym with the best Brazilian jiu-jitsu practitioners in the world for several years? Sure I do, but he's never been in a competition.

"I don't know of any sports he played in high school. He went straight from high school into the wrestling world so there's no college background there. Brock Lesnar was an NCAA Division I champion, who was a champion in junior college, he was a bad ass wrestling in high school and he was wrestling since he was five years old. He was a competitive athlete so that's a different jump to make."

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Heyman said he believes that his former advocate's lack of experience in the competitive world of MMA could be his downfall.

"Phillip Brooks does not have that background," he said. "It makes it all the more improbable, which is exactly why he's so driven to do it."

As for a WWE return, Heyman said as of now there "ain't no way he's ever going back" to the ring after his unceremonious divorce from the company nearly two years ago.

The original founder of ECW also said he doesn't know if he can say that for the future, but right now the only thing on Punk's mind is his debut in the Octagon ... Whenever the hell that may be.

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