Joseph Parker will have to adapt to a late change of opponent for his fight in New York in a fortnight, with Australian Alex Leapai the likely replacement.

Issues with Eric Molina, his original opponent for the fight in Rhode Island on June 29, mean Parker's new promoters Matchroom have had to look elsewhere at extremely short notice, and the Kiwi heavyweight and his team will be aware that such changes can lead to big upsets.

Andy Ruiz Jr's shocking victory over Anthony Joshua recently is a case in point. Joshua was preparing to fight Jarrell Miller before the American's withdrawal six weeks out from the fight due to a positive drugs test. Replacement Ruiz Jr made the most of his opportunity at Madison Square Garden by knocking out Joshua in the seventh round.

Responding to speculation, Parker's manager David Higgins confirmed the Molina withdrawal, which he put down to difficulties in dealing with Molina's promoter, the infamous Don King.

Alex Leapai. Photo / Getty
Alex Leapai. Photo / Getty

"There has been trouble in the background," Higgins told the Herald. "Molina is promoted by Don King. Most people would have probably thought that Don King was dead, but oh no, he's still stirring trouble. It was on again and off again, and he was wanting unreasonable terms. Trying to deal with him has been very, very difficult."

Known as the "Lionheart", Leapai is a 39-year-old with a 32-7-4 professional record. By far his biggest fight was a world title challenge against Wladimir Klitschko in Germany in 2014, a fight he lost by technical knockout in the fifth round. Parker beat Brazilian Marcelo Nascimento on the underard. Leapai last fought in August last year.

"He can bang," Higgins said. "He's still in his 30s and the power is the last thing to go in heavyweights. He has a massive overhand right which can knock anyone out cold."

The late change was "not ideal", Higgins said, but added: "If Joe can't beat Leapai, even if the guy is a big puncher, then frankly he shouldn't be thinking about a re-match with Ruiz."

Parker is the only man to have beaten Ruiz Jr, now the WBO, WBA and IBF champion. Parker and his team would obviously love a rematch but first they have to get past Leapai in the first of a three-fight deal with Eddie Hearn's Matchroom. In the short term a rematch against Dillian Whyte is a bigger priority.