The Next Big Thing?

Former World Wrestling Entertainment star Brock Lesnar is taking his act to another pay-per-view organization Saturday, and his Ultimate Fighting Championship debut has attracted plenty of credibility questions.

Is this a novelty?

Can a first-time fighter beat former UFC champion Frank Mir?

If Lesnar wins, what does that say about the level of UFC competition?

Lesnar and UFC President Dana White say they expected such scrutiny and understand how some mixed martial arts purists want nothing more than to see the 30-year-old former showman defeated in the Octagon when UFC 81 takes place at the Mandalay Bay Events Center in Las Vegas.

"I've got a lot to lose in this," Lesnar said. "A lot of people are watching to see how I make the transition against a credible fighter.

"Let's get one thing straight: Pro wrestling is clearly entertainment. We go out there knowing the outcomes of the bouts. This [UFC] is real."

White said although Lesnar's mug is being prominently advertised on UFC 81 billboards as a headliner because of his WWE-generated name recognition, there is also reason to believe the former NCAA heavyweight wrestling champion has what it takes to ultimately compete for the UFC heavyweight title.

That would be a marketing boon to the UFC, which lost popular heavyweight champion Randy Couture to a contract dispute last year and is now suing the fighter.

"If Lesnar gets past Mir, look out heavyweight division," White said. "I like real fighters, guys who want to fight, and this guy's a real big athlete who'll fight anyone we put in front of him."

Still, skepticism exists at the heavyweight division's highest levels.

Tim Sylvia, who'll fight Antonio Rodrigo Nogueira for the UFC's interim heavyweight title Saturday, said Lesnar was originally "babied" in practices last year with other UFC fighters, and believes there are several peers and intent MMA watchers who "know he's going to get beat."

Couture, in an e-mail, said: "Obviously I have a lot of respect for Brock Lesnar's wrestling ability. He was an NCAA champion, which is an elite group of individuals. I don't think it was a wise choice to jump in and fight a former heavyweight champion.

"He has the potential to be a legitimate MMA contender. But we won't know until he fights legitimate MMA competition."

The 6-foot-2, 265-pound Lesnar has credentials in "real" wrestling, which is considered the essential foundation of an MMA fighter's skill set. At Minnesota, Lesnar was the 1999 runner-up and 2000 NCAA heavyweight champion.