NEWBRIDGE boxing icon Joe Calzaghe believes Floyd Mayweather will be on the money this weekend in his super fight with long-time rival Manny Pacquaio, but admits the American faces ‘a massive burden.’

Few boxers understand the pressure of defending an undefeated record better than Calzaghe and the legendary Welshman believes Mayweather is hampered, not helped, by protecting an unblemished record.

Indeed, Mayweather sensational record of 47 fights, 47 wins, is reminiscent of that of Calzaghe who remained undefeated in 46 professional contests before retiring in 2008, having been a world champion for over a decade.

"There will be a lot more pressure on Mayweather than there will be on Pacquiao," he told BBC Sport.

"Pacquiao has been beaten so he'll be more relaxed than Mayweather. The 'zero' is a massive burden.

"I don't think Mayweather was that impressive in his last two defences against Marcos Maidana. He made hard work of those fights.

"But you can't overlook a guy that's never lost. Mayweather is a fantastic fighter who always finds a way to win so he will be ready for this fight."

Calzaghe believes Mayweather still has the advantage.

"Pacquiao can fight and there's always one great fight left in somebody, but I think the win will go to Mayweather," he added.

Calzaghe insists Mayweather suffers extra pressure due to being in the unique ‘undefeated’ club, with just a dozen fighters ever having ended their careers without tasting defeat.

"When you've been at the top of the sport for so many years, it's your life and it becomes very difficult just to quit boxing and find something else to be happy," he explained.

"Sometimes you're not happy for a while and you get lost but eventually, you do realise that this has to be the end of what you did.

"The older you get, the more it wears down on your body and it takes longer to recover.

"Also, psychologically it's hard to pick yourself up for big fights but, saying that, this is bigger than anything so I'm sure Mayweather will be completely up for this fight.

"It's a fight the whole boxing world is waiting to see."

Floyd Mayweather Snr has backed his son to beat Manny Pacquiao comfortably, but said he wants him to hang up his gloves afterwards.

Mayweather Snr, who fought himself in his youth and now trains his son, has written off suggestions that the May 2 bout at the MGM Grand Garden Arena is an era-defining clash and described the Philippines fighter as just another opponent.

"This era is closed. It's done. Pacquiao is done. He needs to be locked up in jail because it's time to save his a**. Pacquiao needs to lock himself up," he told the Sunday Telegraph.

"He is not on Floyd's level. All he is, is an opponent. That's all he is. Nothing more, nothing less."

Mayweather Jnr, who is famed for his swagger in and out of the ring, goes into the bout with a record of 47 wins and no defeats, with 26 wins by knockout.

But while Mayweather Snr is confident his son can extend that flawless streak next Saturday, he did admit that he would like to see him retire after that.

"I hope that Floyd gets out the game at the right time," he added.

"This is a gambler's game and I don't think Floyd should be gambling too much. Once you reach that pedigree and make that kind of money, you don't have to fight no more.

"I hope he walks away after this fight. Whenever you get in that ring, anything can happen. It looks easy but it ain't as easy as it looks. He makes it look easy."