Is Floyd Mayweather preparing himself for the 51st fight of his career?

That’s the question boxing fans are asking themselves after the 40-year-old released a video of himself training in his gym on Monday.

Mayweather came out of retirement to fight UFC superstar Conor McGregor in August and recorded the 50th victory of his illustrious career. That, it was assumed, was the American’s final bout.

He doesn’t need the money - he topped up his bank balance with a cheque worth $100 million from the McGregor fight - and boasts one of the best professional boxing records of all time.

Taking on any opponent at his age - unless it’s another non-boxer - would represent a significant gamble given his age.

Mayweather beat McGregor with relative ease but was nowhere near his best. It’s clear that his peak years are well behind him.

Boxing fans are all saying the same thing about Mayweather

That said, boxing fans are all saying the same thing after watching Mayweather’s latest training video.

Although he turns 41 in February, the undefeated future Hall of Famer looks incredibly fast and sharp.

The video, which was uploaded to Instagram has been viewed over two million times already, is full of comments from boxing fans expressing their disbelief at his remarkable speed.

Etc etc.

Every time he pops the heavy bag with one of his lightning-quick jabs, it sounds like a gun being fired.

Watch the video here...

That he was wearing a groin protector during the workout has also prompted speculation that he’s sparring and preparing to make a shock comeback.

Who could Mayweather fight next?

But who, realistically, could Mayweather take on in his 51st fight?

There’s no way he will risk his unblemished record, so he’d need an opponent that would guarantee both a huge pay day and an easy victory.

A lucrative rematch against McGregor? Another fight against 44-year-old Oscar De La Hoya, who he defeated back in May 2007?

Watch this space.