Abner Mares knows he is taking a risk by stepping in with Daniel Ponce De Leon in his first featherweight fight this weekend.
The fight between the two Mexicans, for Ponce De Leon's WBC title, provides chief support on the Las Vegas show headlined by Floyd Mayweather vs Robert Guerrero.
Mares is undefeated having won already won titles at two different weights, but goes straight into Saturday's title fight without a previous outing at 126lb.
However, the 27-year-old believes it is something he can overcome despite Ponce De Leon's reputation as a big puncher.
"It's a big factor knowing that I'm stepping into a different weight class, heavier weight class and already going in against a heavy puncher," he said.
"It's hard, but I think it's all mental. I'm going in weighing the same. He's weighing the same that same night and after, I know I'm going to recuperate and I'm going to be at least six to ten pounds heavy the next day.
"I think that night, I want to let it be known that skills and smartness, out-skills power and power and pressure any day. So, I think that's going to be my key and I plan to put it to work on May 4th.
"It's going to be a very, very good fight and I just feel that hopefully on Sunday after the fight, nobody's really talking about Mayweather. I hope everybody's talking about the great that the two Mexicans put on, Abner Mares and Ponce De Leon."
The champion has been in with naturally bigger men like Adrien Broner and Yuriorkis Gamboa and believes his size will be a major factor.
"Basically that is going to be a difference, it is going to be somewhat of a difference and you do have to take it into account," he said.
"I've done it before in my career. I fought as high as 130 and I noticed a difference in size and in power. So, I'm sure that he's going to feel the difference as well. It's hard to just to jump up all of a sudden to another weight class and be fighting for the world title. It's very, very tough.
"But, even though I say that, I'm not going to take it lightly. I'm going to be very, very careful, obviously. I'm going to still think about my game plan and I'm preparing myself as if I'm fighting a solid 126lb featherweight in my division.
"I'm a tough fighter. I'm a pressure fighter. I like to come forward and make fights, which is good and it's going to be a very difficult fight, but I trained hard. I trained very, very hard and I'm going to be ready for the fight."