LAS VEGAS -- The strategy for UFC heavyweight champion Randy (The Natural) Couture appears simple Saturday night at UFC 91 -- put Brock Lesnar where he hasn't been before.

At six foot three, the bulky Lesnar has surprising speed and agility for a man his size. As a former NCAA wrestling champion, he knows how to take down and control opponents. And his striking is improving. The one-time former pro wrestling star literally bowled over Heath Herring with an overhand right last time out.

But the 31-year-old Lesnar has only had three mixed martial arts fights (including two in the UFC). He fell victim to a leg submission in a UFC debut loss to former heavyweight champion Frank Mir and had the upper hand from the get-go in his decision win over Herring.

Lesnar has shown great raw skill, but not been tested in certain areas in his young MMA career. As the 45-year-old Couture notes, he has yet to be in a "firefight."

"I think I have the ability to put him in a whole bunch of places," Couture said Wednesday after working up a sweat in a media workout. "Punch him in the face, kick him in his legs, kick him in his body. Take him down, put him on his back and see how he deals with it."

"Randy Couture will test him," added Couture trainer Shawn Tompkins, a native of London, Ont., who now calls Las Vegas home. "He'll hurt him, he'll hit him and he won't be there when Brock wants to hit him."

Still Couture (16-8) will be giving up 14 years and probably 50 pounds when the two meet at the MGM Grand Garden Arena in what the UFC expects will be its most successful pay-per-view ever,

And the 6-2 Couture has not only fought twice since losing to Chuck (The Iceman) Liddell at UFC 57 in February 2006, coming out of retirement to upset heavyweight champion Tim Sylvia at UFC 68 in March 2007 and then stopping Gabriel Gonzaga at UFC 74 in August 2007.

Couture stepped away again after that, soured by a contract dispute with the UFC. The two sides eventually made up, with Couture opting to return to the fold rather than watch the courts eat up what few years he had left to fight at an elite level.

Both camps have been diplomatic in the leadup to this fight. The normally brash Lesnar was on his best behaviour Wednesday, although he did manage a shot at Couture.

"By the looks of it, to me, Randy looks like he took a year off," Lesnar sniped. "But we're not underestimating Randy Couture. Not at all. He's a pioneer, he's the man. He's got something I dearly want, pretty bad."

Asked to elaborate on his take on Couture's shape, Lesnar suggested comparing a photo of Couture in action against Gonzaga and today.

"I think it's two different Randys. But maybe it's not. I guess we'll soon find out."

"How would he know," snapped Couture when advised of the comment. "Where's he seen me? But that's a typical statement. That's fine. We'll find out Saturday night."

Leading up to the fight, there has been a lot of talk of respect from both camps. But as the bout nears, the lines are becoming a little more frayed.

"We respect him, we respect that he's big, we respect that he's athletic. But we don't respect the fact that he's getting a (title) shot," said Tompkins. "He's not at this level yet. He doesn't deserve to be here. Maybe one day he will, but not today."

Said Lesnar: "I respect Randy and I like Randy, you know, but Saturday night I don't have any respect for him, nor do I like him. It just has to be that way. This is business and he's got something I want. That's the bottom line."

Couture is also not averse to pushing a few Lesnar buttons.

"I think in a lot of ways that brash kind of bravado is covering up a little of the insecurities that he's carrying into this fight because he knows he doesn't have all the skills that he needs."

The Couture camp says while Couture has not fought in more than year, he was training every day with top pros at his Xtreme Couture gym. Plus Couture enters this fight without the nagging injuries he had in his last two outings.

"We've got 28 professional fighters, the highest level of the sport here in Las Vegas at Xtreme Couture and he'll whip all of their asses," Tompkins said. "The average age in that gym is 23 to 28 and that's a long ways from his 45. That's where I put him. He's at the top of the heap in that gym and those guys are no joke."

Lesnar looks as imposing as ever. He will have to lose between 10 and 15 pounds just to make the UFC's 265-pound limit for heavyweights at Friday's weigh-in. He expects to enter the cage Saturday around 275-277.

Couture says bring it on. He's spent the last 10 weeks training with fighters who have ranged from 270 to 330 pounds. And he has shown in previous fights that he can handle bigger men and is a master at executing a game plan.

"I don't need to get bigger and stronger," Couture said. "It's not about going head up with Brock. It's about finding ways around his strength and around his size."

Accurate striking could be the key.

Tompkins says Couture, a two-time alternate on the U.S. Olympic Greco-Roman wrestling team, is one of the few fighters from a wrestling background he has trained who has really picked up striking.

Couture has excellent head movement, an advanced skill in striking, and used it to great effect against the 6-8 Sylvia, who is known for his skill with his fists. Using head movement, inside leg kicks and throwing punches from good angles, Couture effectively negated Sylvia's 12-inch reach advantage and beat the big man to the punch.

"Randy has the ability to figure things like that out and has a good coaching staff that can figure those things out," said Tompkins.

Tompkins also credits Couture's mental game.

"A lot of guys would have broke already, just thinking about fighting a guy like Brock Lesnar, Randy Couture won't break mentally. He's been in there before with bigger guys. This is his game. So I think Brock's in for a world of trouble."

Size won't matter, Tompkins adds, if the bigger man is losing.

"The trick is in a fight like this is to be able to break a person, to hurt them, to make them realize they're not at the same level as you, And that's what he did against Tim, that's what he did against Gonzaga and that's what he'll do against Brock."

But Lesnar also insisted the pressure is all on Couture.

"I've got nothing to lose. I'm not the title-holder -- yet. I'm not feeling any pressure at all, honest to God, I'm not."

Saturday's winner will take on the winner of the Dec. 27 bout between Mir and Antonio Rodrigo Nogueira, who won what the UFC called the interim heavyweight title while Couture was at odds with the organization.