Floyd Mayweather has been urged to pass up the chance to face Ultimate Fighting Championship superstar Conor McGregor and take on Gennady Golovkin after the middleweight world champion pledged to drop down a weight division in order to bring the unbeaten American out of retirement. Mayweather is locked in talks for a cross-code clash with McGregor but a deal is yet to be agreed.

The 40-year-old has accused the Irishman of holding up a deal being finalised to fight later in 2017, after the pair exchanged barbs on social media. Mayweather has not fought since retiring after beating Andre Berto in September 2015 to extend his unbeaten winning record to 49 fights.

Golovkin is considered by many to be the best pound-for-pound boxer on the planet, having captured the WBA, WBC and IBF world middleweight titles. The Kazakhstan fighter has been chasing a money-spinning unification bout with Mexican Canelo Alvarez, but the pair continue to dodge each other's advances.

WBA regular middleweight title holder Daniel Jacobs is Golovkin's next opponent on 18 March, yet he has already turned his attention to the future. "Especially for Floyd I would go to 154lbs or 160lbs, if he wants," he told ESPN. "This is the dream fight. There is a big difference between Floyd and Canelo. Floyd is Floyd; he is the best pound-for-pound. Canelo is nothing. I spoke with him last year, I want this fight and I need this fight. I'm tired of talking too much. I don't respect him because he's selfish."

Triple G stopped Kell Brook in London last September in his most recent outing, a performance which provoked Mayweather into suggesting he should move up a weight class. Mayweather himself has indicated he will only come out of retirement to face McGregor in a boxing match, but revealed his nephew tipped him to beat the undefeated middleweight.

"What we want to see is this: we've seen Sugar Ray Leonard go up in weight, Roberto Duran go up in weight, we've had so many legendary fighters go up in weight but my nephew's favourite fighter, Triple G, has yet to go up in weight," he told reporters in Las Vegas, according to Boxing Scene.

"I see my nephew after the Kell Brook fight and he said [Golovkin] 'wasn't what I thought he was, he cool'. I told you he's got punching power for a stationary target. Then he said 'unc, you would have stopped him, you would've destroyed him'. I said 'nephew, you ain't telling me nothing new'. He was just a fan of Triple G fighting those stationary targets."