With the super fight between Floyd Mayweather and Conor McGregor expected to earn the pair an estimated $100 million dollars each, Mayweather has sent his opponent an ominous warning ahead of August 26.

Videos have emerged of Mayweather's return to training and it is safe to say the 40-year-old hasn't exactly let himself go.

Mayweather looks to be in very good shape considering he has been out of the sport for two years following his retirement in September 2015 after victory over Andre Berto at the MGM Grand in Las Vegas.

TMZSports have posted another new video on YouTube which showed further evidence that the 40-year-old was taking his training seriously as they managed to capture the first glimpses of the American working the heavy bag and more importantly, sparring in an LA gym yesterday.

Mayweather is aiming for a 50-0 fight record when he takes on MMA star McGregor in August and seems to be full of confidence as the 40-year-old was seen prowling around the LA gym.

“You name them, I'll beat them," the unbeaten star was heard saying - scroll down to see the video.

“I could get a black eye, a bloody nose, I could have a bad day in the gym but at the end of the day, I don't have a bad pay day and I don't have a bad night under the lights,

“I get bumps and bruises, but I don't have a bad night.”

But we think most fans will more interested to see what Mayweather looked like back in the ring and as the video below shows, ‘Money’ still looks very good moving around the ring - skip to 0:45 to see the sparring session.

What started as a slow and gentle session, quickly began to pick up the pace as the 40-year-old started to get into full flow, sending a flurry of shots his opponent’s way.

Perhaps now McGregor can see what he has got himself into! After the Irishman and MMA president Dana White spent months goading the American boxing legend out of retirement.

McGregor has never boxed professionally in his life and on this evidence, a victory against one of the all-time greats would be an even bigger shock than everyone already thinks.