Amir Khan, who had campaigned to fight Floyd Mayweather Jr. in the American's swansong, paid tribute to the pound-for-pound king after he hung up his gloves following his 49th straight win.
Mayweather dominated Andre Berto over twelve rounds last Saturday night at the MGM Grand in Las Vegas. Both Khan and Berto are trained by Virgil Hunter.
"I' m obviously very upset I didn't get the fight," added Khan to Sky Sports. "We have to remember him as a great fighter. He was a very good fighter, what he did in boxing, all the entertainment, the showbiz and everything.
"Not a lot of people liked him, people thought he was very arrogant or disrespectful but that's what type of character he was.
"He was just nice to watch, he was just one of those funny guys to watch, but in the ring he backed it all up with his boxing skills, speed and power.
"He is going to be remembered as a great fighter, obviously I am upset I didn't share a ring with him and give him his first loss because I really believed I had the tools to do that but he's always going to be remembered.
"Who knows, he might come back for the 50th fight, I can't see him retiring. I know what Floyd Mayweather is like; I've spent time with him, I've been in the gym with him, he's a guy who can't stay in one place.
"So I really believe he will come back for that 50th fight and I really think he will go for that Amir Khan versus Floyd Mayweather fight."