Velasquez's head trainer Javier Mendez makes the case as he spoke with Sherdog:
"[Lesnar] is an extremely hard fight for us," Mendez said. "We’re going to definitely have to win the standup game and the kicking game. And then the wrestling, the size of Brock could potentially neutralize us, but Cain’s cardio is going to neutralize him, so it’s going to be a really, really interesting fight."
"Should Carwin get past Lesnar, it’s going to be a little different fight," Mendez said. "We can’t attack the same as against Lesnar because Carwin is to be respected because of his incredible power, and his wrestling is top notch also. We will have to take a different path because he is a different fighter with different strengths."
I think both fighters are a tough fight for Velasquez. He doesn't really seem to possess KO power with his stand up game, and both Lesnar and Carwin are absolutely huge. While Rothwell was huge compared to Velasquez as well, Rothwell doesn't have near the wrestling pedigree that they have. So it would be interesting to see how he stacked up against either Lesnar or Carwin. Mendez elaborates further on why Velasquez should be next in line for a title shot:
"If you look at the records of all the heavyweights, Cain is 5-0 [and] I don’t think there has ever been a UFC heavyweight who has gone 5-0," said Mendez. "Who is there left for us to fight that’s not in title contention? Frank Mir, Nogueira … they’re all top guys. Carwin, Lesnar is the champ. I feel that now, we can fight the champion now. To me, they’re all interchangeable. They’re all just as tough. They all have their strengths."
It's being rumored that Velasquez could help headline a show in Mexico City in the early quarter of 2010. However, if Velasquez gets the winner of Carwin/Lesnar, where does that leave Nogueira?