Lesnar must cut down to the heavyweight limit of 265 pounds before Friday's weigh-ins, but by the time the two enter the cage he probably will outweigh the 225-pound champion by at least 50 pounds.

"His size provides some interesting problems for me that I have to try to solve," Couture said. "That made it an intriguing matchup for me."

Despite a 15-month layoff from competition mostly because of a lawsuit he filed against the UFC in an attempt to get out of his contract, Couture remains the heavyweight champion.

With the legal issues settled, Saturday's fight is the first bout of what essentially amounts to a four-man tournament to determine the undisputed titleholder.

On Dec. 27, interim champion Antonio Rodrigo Nogueira will fight former champion Frank Mir, and the winners of the two bouts will meet sometime in 2009.

In order to get to that point, the 45-year-old Couture first must beat the 31-year-old Lesnar, who is getting a shot at the belt despite a 1-1 UFC record.

Though Lesnar is best known for his time as a star attraction for World Wrestling Entertainment, he was an accomplished wrestler at the University of Minnesota, where he won an NCAA title in 2000 and placed second in 1999. But he made his mixed martial arts debut just last year.

Couture's head trainer, Shawn Tompkins, thinks his fighter's experience will carry him to victory. "He's big. He's athletic. He's young. He's powerful," Tompkins said of Lesnar. "But he's not Randy Couture, and he never will be."

Tompkins brought four large wrestlers into camp for Couture to train against on a daily basis. "We were able to see the mistakes he made against them and correct (those)," Tompkins said.

As for strategy, Couture plans to test Lesnar's ability to handle adversity. "We haven't seen him on his back, and I certainly have the ability to do that to him," Couture said.

Lesnar, a native of Webster, S.D., thinks his size will be an advantage but knows Couture will be ready.

"I certainly wouldn't like going against a guy 50 pounds bigger than me, but Randy is a smart fighter," Lesnar said. "The guy's been training to fight me for 10 weeks. He's proved himself over and over.

"You can't underestimate Randy Couture."

After training the champion for about two years, Tompkins came to a similar conclusion.

"One thing about Randy is you never bet against him," Tompkins said.

• NOTE -- Amir Sadollah has withdrawn from his bout against Nick Catone because of a leg infection. With no replacement fighter available on such short notice, the card now will feature just 10 bouts. The fight between Dustin Hazelett and Tamdan McCrory will be moved to the main card.

Contact reporter Adam Hill at ahill@ reviewjournal.com or 702-224-5509.