Amir Khan
Amir Khan had challenged Floyd Mayweather in the past as well, but to no avail.Reuters

Floyd Mayweather retired after his last fight against Andre Berto in September last year. British boxer Amir Khan was disappointed when the American decided to fight Berto in his farewell bout, when Khan was one of the top contenders.

This was not the first time that the boxer was overlooked for a fight against the American. Amir Khan also missed out on fighting Manny Pacquiao, after the Filipino decided to face Timothy Bradley in his last fight in April, with it dampening Khan's spirits of fighting a top-level boxer.

Khan, though, has not given up on his fight against the retired Mayweather. However, the British boxer needs to focus on his next bout for now, against Canelo ' Saul' Alvarez in May. The bout against Alvarez is not going to be easy as the Mexican has only lost one of his 48 bouts. He has won 46, with one draw.

The match against Alvarez is one of the toughest in Khan's career and experts are already tipping the Englishman as the underdog, which is new to him.

"No, it's the first time [I've been such a big underdog]," Khan said in a Q&A with former boxer David Haye.

"It's the first time because when I normally fight, I've always been the favourite to win."

The bout is said to be a big one for Khan, who seems to be confident of beating Alvarez. If Khan loses, he will not be able to even think about tempting Mayweather out of retirement, but with a win, he can put across a challenge to the American. With Alvarez being one of the best opponents Mayweather faced in his career, a win may force him out of retirement.

And if the public demands a Khan vs Mayweather fight, it might just happen.

"Once we beat Canelo we want to go on and fight the biggest names in boxing and if Mayweather still says he's retired and doesn't want to ever come back then I think it shows that he knew something that you people out there don't know -- that I would beat Mayweather," Khan said.

"It didn't happen but in a way, getting you guys to demand that fight once we beat Canelo, you guys say, 'look - we want that Khan-Mayweather fight', that's when we will see that fight happen."