Former undisputed cruiserweight and heavyweight world champion Evander Holyfield considers Floyd Mayweather Jr. to be a great fighter - but he also points out that the retired pound-for-pound king missed the boat by not making attempts to become an undisputed champion.

Mayweather won titles at super featherweight, lightweight, junior welterweight, welterweight and junior middleweight - but he was never the undisputed champion in any of the five divisions.

The closest Mayweather came to cleaning out all of the titles was in 2015, when he defeated Manny Pacquiao in a WBC, WBA, WBO welterweight title clash. After the fight, Mayweather refused to pay the WBO a sanctioning fee and he was stripped of the belt.

Mayweather retired for good last August, when he raised his record to 50-0 with a stoppage win over UFC superstar Conor McGregor, who was making his professional boxing debut.

The retired boxer feels a sense of pride for capturing the WBC title in five different weight divisions, but Holyfield feels that is not enough - that Floyd needed to fight the other champions and beat them too.

"My whole thing [is this], he is a great fighter. But to actually say that [he's beaten everyone], you've got to be the undisputed. You need to get all the belts at one time and let everybody know that I beat everybody who had a belt and I am undisputed. You can't just say 'I got this WBC belt, I got this WBC belt and I got this WBC belt,' and all of them are WBCs and you don't got the rest of the belts to say you are undisputed," Holyfield told Kevin Iole of Yahoo Sports.

"The whole big thing is, its not just this one belt - its all of these other belts. I wanted to be undisputed, where you can say that I am the undisputed champion of the world. Ever since [Muhammad] Ali left, there wasn't an undisputed champion until [Mike] Tyson was the first one to be made undisputed, then Buster Douglas, then me, then Riddick Bowe and then Lennox Lewis. Lennox was the last one [at heavyweight]. That was five guys who took the time and said 'I don't just want to be one of the champions - I want to be undisputed where everyone knows at that time that I was the very best.

"That's the only thing that Floyd is missing, because he was never the undisputed world champion in any weight division."