David Haye knows he is heading into "uncharted territory" when he attempts to wrest the WBA heavyweight title from man mountain Nikolai Valuev on Saturday.

The former undisputed cruiserweight champion has had only one top-level heavyweight contest, beating Monte Barrett by stoppage a year ago, and after a bid to dethrone Wladimir Klitschko in the summer fell through due to injury, tries his hand against 7ft 2in Russian Valuev in Germany.

The outspoken Londoner, 29, realises the size of the task facing him in Nuremberg but believes he can emulate his hero Evander Holyfield by moving up in weight to win a portion of the heavyweight title.

"Fighting against a guy who is 7ft 2in and 24 stone is uncharted territory for me, I'm used to fighting guys at cruiserweight, which is 14st 4lb," Haye (22-1, 21KOs) said.

"No British cruiserweight has ever gone up and won the heavyweight title so I'd be making history.

"Evander Holyfield is the only other unified cruiserweight champion in history to go up and do the same thing at heavyweight.

"I've got an opportunity to go out there and equal what he did by becoming the second to do it."

Haye beat undisputed world cruiserweight champion Jean-Marc Mormeck on foreign soil to take the WBC title before unifying the belts with a spectacular second-round stoppage of domestic rival Enzo Maccarinelli in March last year.

Since then he has boxed only once, stopping faded former contender Barrett in five rounds in London last November.

He does not expect ring rust to be a problem, however.

"It's going to be almost a year to the day since I've actually been in a ring," he said.

"I've been training, though. It's not like I've been sitting on a beach getting drunk.

"I've kept in shape the whole way through, I obviously trained for the fight with Wladimir Klitschko so it's not like my body hasn't been in shape. I just didn't have the fight at the end of it."

Valuev's trainer, Alexander Zimin, has tailored their preparations specifically for the Englishman's style.

"During our preparations we have considered the individual manner of David Haye and also his size and weight," Zimin said.

"We have prepared very well for him. We have also chosen the sparring partners very well who are similar size to David and a similar style.

"Of course we have also used our experience from previous fights against very good opponents and did a lot of conditioning work for Nikolai generally.

"We've also done a lot on tactics and technique."