Cole Miller doesn't just think CM Punk will be adequate as a UFC fighter, he thinks the former WWE star will be a winner.

"This guy doesn't just have a chance," Miller told MMA Fighting. "He's gonna kick somebody's ass."

Miller, a UFC veteran of seven years and 16 fights, has trained with CM Punk on multiple occasions and vouches for the divisive signee's skills on the ground. Miller is coming from a base of knowledge, too -- he's a black belt in Brazilian jiu-jitsu and one of the best grapplers in the lightweight division.

"I think he'll do very well," Miller said. "I don't think he's trying to make a 10-year career out of this. But he's going to shake things up, whoop some ass and prove a lot of people wrong. I expect him to do very well against whoever they put up against him."

Punk has said that he has not advanced past a white belt training with Rener Gracie. That is more out of desire than anything else -- CM Punk said he isn't interested in moving through the belt system because he's always learning. Miller estimates that Punk, whose real name is Phil Brooks, is far past a blue belt -- and a better grappler than many fighters in the UFC.

"I think most MMA fighters don't have any kind of ground," Miller said. "Most of them aren't good at all. Even in the UFC. There are plenty of exceptions, but when I say most, I mean more than 50 percent are nothing more than OK blue belts on the ground. I would rate CM Punk definitely above that."

The UFC's signing of Punk, the popular former WWE champion, has come under scorn from some. The biggest argument is that he is not deserving of competing in the UFC, MMA's biggest stage. CM Punk admitted himself on FOX Sports Live on Wednesday that the point is probably accurate. But, of course, from a marketing perspective, there's little doubt his fights won't bring a ton of attention.

The other criticism has been that Punk is a privileged celebrity allowed to skip the line without paying his dues. Miller doesn't have any sympathy for those who make that claim.

"So what?" Miller said. "Get over it. The UFC is a business and I guarantee it's definitely into protecting its brand and business. If you think they would sign somebody that's gonna go in there and suck and is not skilled, you're crazy. When did you see somebody in the UFC that completely sucked? Never."

Miller also thinks some of the negativity has come from the stigma against scripted pro wrestling. Miller said Punk likely went through a tougher road to get to the top of WWE than most MMA fighters had to get to the UFC. CM Punk has been known as an overachiever and someone wrestling insiders never expected to become a bonafide WWE draw.

"It's a hating society," Miller said. "People come out of their shell and s*** on whoever the first chance they get. People want to write that pro wrestling is fake. Pro wrestling is not fake. It's pre-determined. The guys at the highest level have to have an indomitable spirit.

"This guy has the perseverance it takes. He's been through the fire. Most people are gonna break training for their first MMA fight and realize they don't have to. This guy has been through the gauntlet, so to speak."

Another reason Miller thinks CM Punk will be successful is his pride and determination. He has chosen to leave pro wrestling, where he is a megastar, to wade into a new and dangerous sport, solely because it is his dream.

"You think someone like him is going to just make a mockery of themselves in another area?" Miller said. "This guy was the best wrestler in the world. He's not gonna go into the UFC to lose, I promise you."