Joseph Parker's trainer Kevin Barry says the New Zealand heavyweight has improved massively since his impressive knockout of Francois Botha in June.

Parker, weighing in at 102kg, has put in more than 320km of road running and 85 rounds of sparring in Las Vegas in seven weeks ahead of his fight against Afa Tatupu for the New Zealand National Boxing Federation title at Auckland's Trusts Arena on October 10.

The fight was arranged following the postponement until November of the David Tua v Alexander Ustinov bout originally scheduled for Saturday and at which Parker was to appear on the undercard.

"We had a real tight schedule before the Botha fight,'' said Barry. "We only had eight weeks together and every day counted.


"But since I have got him back to Las Vegas we have been able to be a bit more relaxed and I have been able to introduce Joseph to a lot more things.

"Joseph's body is changing. His strength is improving. His boxing knowledge is being extended every day. He is already a different and a better fighter to the one who beat Francois Botha.''

Both 21-year-old Parker and Tatupu want to unify the NZNBF belt with the New Zealand Professional Boxing Association belt Sonny Bill Williams won when he beat Clarence Tillman.

That fight was 18 months ago and so far Williams has successfully avoided having to defend the title, most recently ducking a call-out from Tatupu.

Tatupu, who works in a timber yard, will train fulltime during the month before his fight against Parker. He has a nine-win, four-loss record but is known as an extremely hard puncher.

Parker is unbeaten over his six fights.

Parker's promoters Duco Events also announced this morning that they have signed light heavyweight Robbie Berridge to their stable on a six-year deal.

Berridge, 28, is a hard-hitting southpaw with only one loss in 22 fights.