Alex Arthur said yesterday that he feared the worst the moment he heard that Ricky Hatton had signed to fight Floyd Mayweather, because he has seen at close quarters the power and the speed of the undefeated five-weight world champion.

Arthur, the WBO interim super-featherweight champion, who will defend his crown against Steve Foster at Meadowbank this weekend, spent time in the same Las Vegas gym as the man regarded as the best pound-for-pound fighter in the world.

The 29-year-old Edinburgh fighter believes after that experience that Mayweather might be unbeatable. Arthur recalled: "I first met Ricky when we were 16-year-olds, during our amateur days, and we have been mates ever since. But when I was asked how Ricky would do against Mayweather, I replied that for anyone to beat him, he would need six arms and two guns.

"It's not fair that Mayweather is allowed to fight other humans because he is from out of this world. Mayweather's reflexes are so unbelievable that there were guys turning up at the gym trying to hit him and they could not manage to do that even once.

"So, considering what he was up against, Ricky did tremendously well to last as long as he did."

Arthur's meeting with Mayweather took place nearly two years ago and he believes that encountering him was an inspirational experience.

He added: "Mayweather is actually similar to me, in as much that he is a family man who wanted to talk about his kids all the time."