All the signs indicate that five-division world champion Floyd Mayweather Jr will comfortably maintain his unbeaten record when he faces Argentina's Marcos Maidana on Saturday, though the American is not expecting a "pushover."

Mayweather, who has a 45-0 record with 26 knockouts, is an overwhelming 11-1 favourite for the WBC/WBA welterweight title unification bout which will be staged at the MGM Grand Garden Arena in Las Vegas.

Not only is the experienced American widely regarded as one of the best defensive fighters of all time but he is a natural welterweight whereas many critics believe that Maidana moved up too quickly from the 130-pound level to the 147-pound division.

"Everybody thinks he's just going to be a pushover, but I don't think so," Mayweather, 37, told reporters while preparing for Saturday's showdown. "That's why I'm training hard and I'm pushing myself to the limit every day.

"If he brings his best, maybe he will be the first guy that actually makes me dig in my bag of tricks and pull out my 'A' game.

"Hopefully he will make me bring out my 'A' game because my whole career all I had to use was a 'D' and 'C' game to beat every guy."

Maidana, who won his most recent bout in December with a unanimous decision against the heavily favoured American Adrien Broner to claim the WBA welterweight title, is known for his all-round skill and blistering power.

Asked what he thought the Argentine slugger did best in the ring, Mayweather replied: "Well, he punches extremely hard if he has an 80 percent knockout ratio.

"That's obviously his best attribute, but a lot of times when a guy's swinging a lot of big shots and they're not landing, you get fatigued like that.

"I may be the hardest puncher he ever fought. He hasn't been hit by me yet, so we'll just have to see if he's the hardest puncher."

Mayweather, who outboxed Saul Canelo Alvarez in his most recent bout in September to take the Mexican's WBA and WBC super welterweight titles, has repeatedly spoken about the need for patience against Maidana.

"Maidana is hungry, he's ready and he has a great knockout ratio," said the brash American, who is nicknamed "Money" for his flamboyant and often extravagant lifestyle. "It's all about keeping composure and sticking to the game plan.

"We're going to take our time, go out there and if a guy leaves an opening on his face, we're going to take it, if he leaves an opening on his body we're going to take it.

"But we can't just say we're going to go in there and everything is going to go to the body. We're going to take our time and pick the guy apart. I'm naturally the bigger guy because I've been at 147 almost 10 years now."

Maidana, 30, has an impressive professional record of 35-3 with 31 knockouts and oozed confidence ahead of Saturday's fight while readily conceding he is a big underdog.

"I know people think I'm going to lose, but I come to win and I'm not afraid of anybody or anything," said the Argentine. "I have the support of the Latino people and I'm coming to win."

Saturday's fight, scheduled for 12 rounds, will unify the WBC welterweight title held by Mayweather and Maidana's WBA welterweight crown.   

"If he brings his best, maybe he will be the first guy that actually makes me dig in my bag of tricks and pull out my 'A' game" - Mayweather

Amir Khan will also fight on the undercard as he goes head to head with Luis Collazo in Las Vegas.

Khan appeared set for a showdown with the undefeated Mayweather, but the American instead chose to fight Maidana in a world title unification bout.

But rather than sulk, the 27-year-old from Bolton agreed to star on the undercard and will make his welterweight debut against Collazo, a rugged southpaw from New York who has won his last four fights, which includes a shock second-round knockout victory over former 147lb world champion Victor Ortiz.

While Khan is refusing to look past the 33-year-old (35-5, 18Kos), he hopes a dazzling display will put him in the shop window for a lucrative showdown with Mayweather later this year.

"As long as I put on a great performance I'll earn that shot [at fighting Mayweather]," he said at the final pre-fight press conference.

"But, to be honest, I'm not looking past Collazo. I need to win this fight and take it from there. I need to put on a good performance and we'll see what happens."

The other main fight taking place on the Mayweather undercard sees Adrien Broner take on Carlos Molina.