Q&A on Lesnar-Velasquez, UFC 121

SI.com caught up with Sports Illustrated senior writer Jon Wertheim to talk about Saturday's UFC 121 card at the Honda Center in Anaheim, Calif.

SI.com: UFC heavyweight champion Brock Lesnar is defending his title against Cain Velasquez in Saturday's main event. What do you make of this fight?

Wertheim: They're both great wrestlers, Lesnar's just got 10 years of experience on this guy. You get the feeling Velasquez is a future champion, just not this time.

Lesnar is more experienced, if not in MMA than just in familiarity with the big occasion. It's pretty rare that a guy would be fighting for a heavyweight title with eight UFC fights like Velasquez. (Of course, Lesnar did it too, winning the belt from Randy Couture in just his third UFC bout.) It's a great fight if you're a fan. This is what separates MMA from boxing; if this were boxing, this fight would never happen because they'd bloat his record to 30-0 before they put him in there. So I think Velasquez is a future heavyweight champion, I'm not quite sure he's ready. But Lesnar had a tough fight with Shane Carwin at UFC 116 in July and was forced to show a lot to pull that fight out.

SI.com: Many have said Carwin exposed vulnerabilities in Lesnar's striking game that Velasquez can exploit. Is it fair to say a stand-up fight benefits the challenger?

Wertheim: You can hit Lesnar. Problem is, Lesnar can take a punch. It'll be interesting to see where this fight ends up, because both of these guys actually can stand up and fight on the ground. This is the biggest fight of the year for UFC. Heayvweights are always the big draw, but these are the two best heavyweight candidates out there. If you're a fan, this is a fight to buy.

SI.com: The oddsmakers have listed Lesnar as a healthy favorite to retain the title. What are the realistic chances of the belt changing hands?

Wertheim: I think there's a real chance of an upset. A lot depends on how Velasquez handles the moment. He's never had a title fight. He's also never had a fight quite like this. They've moved him up pretty quickly here, but the guy's looked great in his first eight fights. If he can catch Lesnar coming in, it's not hard to see this fight going to Velasquez -- you just wish he was a little more experienced.

SI.com: What else are you looking at on Saturday's card?

Wertheim: It's a great card. Some of these UFC cards recently have been a little thin. Not Saturday. There's Tito Ortiz vs. Matt Hamill and Diego Sanchez vs. Paulo Thiago. They've really loaded up for this one. The other big plotline is Jake Shields in his first UFC fight since coming over from Strikeforce, where he knocked off Dan Henderson in April. It'll be interesting to see how he fares in UFC now. He's a top-five talent, but it's always a little different to make the transition to UFC.

And you've got Tito Ortiz coming back for the first time since November. Ortiz-Hamill is the fourth fight down on the bout sheet. Any time you've got Tito Ortiz --- even at this stage of the game -- at fourth down on the main card, you've got a pretty good card going.

Even with as many cards as UFC does, it's rare to have events on back-to-back weekends. But compare last Saturday's London card to this one, from top to bottom, and it's a big difference.