Kiwi heavyweight boxer Joseph Parker has been thrown a curve ball following the withdrawal of Sherman Williams due to a contractual issue ahead of their scheduled showdown in Oberhausen, Germany, on Sunday.

Having already adjusted his approach following the unavail-ability of undefeated Ukrainian Andriy Rudenko, Parker now faces more disruption in his build-up.

Parker and Williams were set to meet on the undercard of Wladimir Klitschko's world heavyweight title defence against Australian Alex Leapai.

"Tank" Williams has refused to fight Parker after being thrown out of Klitschko's training camp, where he was sparring with the world champion, and is breaching his contract by refusing to step into the ring.


The 41-year-old has flown back home to Florida, with Klitschko's K2 management team now demanding boxing authorities slap the 1.80m Bahamian with a six-month ban.

It leaves Parker's promoters no choice but to find a new opponent, 1.96m Brazilian Marcelo Luiz Nascimento (17-5).

The 33-year-old, who goes by the nickname "The Hammer", forged a strong start to his career, stopping his first 13 opponents inside the distance.

That impressive run booked Nascimento a date with undefeated British talent Tyson Fury at Wembley Arena in 2011.

Fury emerged the victor, with the fifth-round stoppage as Nascimento succumbed to a monster right hand from the now 22-0 Brit.

Nascimento may have taken the fight with Parker at short notice but has a height advantage and plenty of experience and will fancy his chances against the 7-0 South Aucklander.

"We're genuinely worried about this fight," Duco's Dean Lonergan said. "It tests Joseph in a way we didn't want to test him. He's gone from fighting a short opponent to fighting the biggest man he's ever faced. Kevin Barry doesn't have much time to rework the fight plan after Sherman got scared and refused to fight. Nascimento is obviously not scared of Joseph and must be tougher than Sherman."

Meanwhile, Klitschko says he plans to box on for another decade in his bid to break Joe Louis' record as the longest-reigning world heavyweight champion.

The 38-year-old has been world champion since 2006. He has no plans to retire and wants to break American boxing legend Louis' record of 12 years as a world heavyweight champion, having been unbeaten between 1937 and 1949.

The Ukrainian needs to fight on for four more years, until 2018, when he will be 42, to set the record as the longest reigning champion.

Daniel Richardson is in Germany courtesy of Duco Events.