Retired former five division world champion Floyd Mayweather Jr. believes WBO super featherweight champion Vasyl Lomachenko is being underpaid by his promoter, Bob Arum of Top Rank.

Mayweather challenges Top Rank - which the unbeaten fighter now refers to as Bottom Rank - to present a list of the paydays that some of their stars have made in the last twelve months - and Mayweather says that he will explain why all of them are underpaid.

One fighter in particular who Mayweather claims is underpaid - is Lomachenko.

Mayweather feels Lomachenko was grossly underpaid for his recent win over Guillermo Rigondeaux.

“Now look. He got $1.2 million. This is a guy who won two gold medals and this is the guy they are talking about as the pound-for-pound, the best fighter in boxing, he's making $1.2 million. I would rather be not known as the best pound-for-pound fighter in boxing and get paid $6, $7 or $8 million a fight. That's just my look at it. If you want to take bigger risk, you can get rewarded," Mayweather told Fighthype.com.

"I take nothing away from Lomachenko. He has to look at his promoter. He's been treating fighters bad for over 40 years. As soon as I got away from him, as soon as I got away from Bob Arum - instantly I started making crazy money. If Lomacheko got $1.2 million and the other boy got $400,000 - that's $1.6 million [combined and] I got fighters making that.

"I thought this was some huge fight, some colossal fight. If its that big of a fight, the money has got to be better. So Lomachenko, tell your promoter to pay you. I like you. I like his movement, his speed. I respect him as a fighter. At the end of the day, learn the business part. Tell your promoter to pay you. You got $1.2 million and you should have got $2.5 million."

“If Bottom Rank is a top company in boxing – all I want to do is – I wanna see the paydays. We going to pull up the paydays from the different fighters at Top Rank. We going to pull up the paydays and then I’m going to show you what these guys should be getting and why they are underpaid.”

Lomachenko had recently been calling out one of Mayweather's fighter, Gervonta 'Tank' Davis.

The Ukrainian boxer has claimed that Davis is hiding from the fight - a claim that Mayweather denies.

“Tank has a promoter. Tank”can come to me and say Floyd, this is the fight that I want. At the end of the day I’m going to say there is no rush. You’re still young. If you want to fight there’s plenty of fights. You’ve got a lot of fights left in you. You’re only 22 or just turned 23 years old. He's got 15 years left. But if you rush and take all of the hard fights now, then you won't make it to 38 or 39 in the boxing business. There is no rush," Mayweather said.

"At the end of the day, I got nothing against Lomachenko. Just don't try to disrespect any fighter who is with me. Tank ain't hiding from you. Tank wants to fight you. He asked me about fighting you on more than one occasion. Me, as a mentor and father figure, I told him there is no rush."