Although boxer David Haye is the bookies' odds-on favourite to win his clash against the Cobra on Saturday, May 21, he knows he's taking a risk.

The former WBA world champion is up against an undefeated bruiser in Arnold Gjergjaj at The O2 – and at 35, a defeat would end his comeback dreams.

Although he holds out the hope of taking on Anthony Joshua, an unlucky punch or silly injury could send him into retirement a second time.

Ahead of the clash, he said: “Every fight has to be perfect, so I can’t be getting injured or losing. Time is ticking away.

“Anthony Joshua is 10 years younger than me. If I want to become world champion I can’t take a couple of years to work my way back. I can’t allow myself to unravel or come unstuck at this stage.”

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Although the Kosovo-Albanian has a 29-0 record with 21 stoppages, he’s fought no-one in the class of Haye, but even an outsider can have his day.

Trainer Shane McGuigan has been crucial to getting the Bermondsey boxer back into disciplined, focussed ways.

McGuigan said: “When he was fighting before, he was fighting and then going off on holidays a lot because of injuries. He was spending a lot of time away from the gym. Now he’s fit and healthy, I want to keep him in the gym as much as possible.

“We’ve been in the gym non-stop and he’s enjoying his training, which is the most important thing.”

David Haye and Arnold Gjergjaj will go fist to fist at The O2 on May 21

Haye’s physique has come in for comment, with former champion Lennox Lewis saying that the boxer has sacrificed speed for strength.

Haye weighed in at 16st 3lbs for his first Haye Day against Mark de Mori – more than a stone heavier than his previous bout in 2012.

Haye said: “I completely understand what Lennox is saying. Being bigger is not necessarily being better.

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“I’ve been sparring with George Groves this week for speed, so I’m used to a super-middleweight’s speed, so when I get in the ring it will seem like it is in slow motion.”

Arnold Gjergjaj, who is now Swiss, said: “I respect The Hayemaker but his time is over and I’m coming to win. I’m unbeaten and I intend to stay that way.

“This is the biggest fight of my life and it is an opportunity I will not waste.”

There are s till some tickets left for the fight , which will be broadcast for free on Dave. Coverage starts at 8pm with the Haye fight due about 10pm. Entertainment will include sets from Lethal Bizzle and Fatman Scoop. There are nine fights on the undercard including an outing by 44-year-old Shannon Briggs, likely to be Haye’s next opponent.