How do you beat Usain Bolt?

Usain Bolt will still have to fight to retain his 100 metres world champion title at this weekend’s final in North Korea, despite the absence of Tyson Gay and Asafa Powell, according to fellow sprint stars.

Maurice Greene, once the world’s fastest man, has sensationally predicted that the men’s final at the world athletics championship in Daegu on Sunday will see the Jamaican superstar eclipsed by training partner Yohan Blake.

Greene said the 21-year-old, who is also Jamaican, “is crazy enough, mentally tough enough to believe he can go out there and actually win”.

“I don’t think Blake is fearful of Bolt,” he added.

Bolt is not the same 9.5 runner that he was. Maurice Greene

Greene said Bolt, whose world record is 9.58 seconds, “is not the same 9.5 runner that he was”.

“He is allowing himself subject to getting beat. That is why I say someone can come up and take him.”

Gay, considered a leading challenger until a hip injury saw him pull out of the championship, disagreed, saying: “Usain, he is the favourite. He is a championship performer and I think he has an advantage.”

Powell, who pulled out of a hotly anticipated showdown with Bolt after suffering a groin strain on Thursday, backed Gay, saying: “It’s not going to be an easy race based on the times this year. But he (Bolt) is the more experienced one and he’s used to winning so he might have the best chance.”

The absence of Gay and Powell and doping suspensions for Jamaica’s Steve Mullings and American Mike Rodgers have cast a shadow over the final, which follows evening heats on Saturday.

But Greene said: “It is still going to be one of the closest races in the championship.”

Channel 4 News’s Keme Nzerem writes from South Korea:

“Usain Bolt says he’s not a legend yet – but he’s working on it.

“He improved on his own world record in 2009 by the biggest increment in the history of the flagship sprint.

“But last year was written off to injury, and this season six men have run faster than him.

“Yes, he races on Sunday as the favourite, but a world record is looking unlikely, and even a victory is by no means a foregone conclusion.

“His closest challengers aren’t here in Daegu – Asafa Powell, his mentor and one of the only people to have ever beaten him, is out with a groin injury; the only other man to have shown Bolt his heels is Tyson Gay – also out, with a bad hip. And two of the fastest men this year – Jamaican Steve Mullins and American Mike Rodgers – recently failed drugs tests.

“But that still leaves a phenomenal field, many of whom are capable of running 9.8 seconds – a time that a decade ago would broken the world record.

“So the winner is not a foregone conclusion. In 1999 Maurice Greene ran 100m in 9.79. Only a handful of sprinters have ever run faster. And he’s tipping a new kid on the blocks – Jamaican Yohan Blake – to deliver Bolt, and Daegu stadium, a massive upset.

“He’s young and he runs without fear”, Greene said today. “Not to take anything anyway from Bolt – but he’s not been great this year – and there’s gonna be a surprise.”

It’s all mental.Otherwise you’ve already beaten yourself. Tyson Gay

So how do you beat Bolt? Tyson Gay says he meditates.

“It’s all mental”, he says. “Otherwise you’ve already beaten yourself.”

If the challenge is big racing against Bolt over 100m, consider his favoured event – the 200m. Bolt’s secret is quite simply his height. He needs fewer steps to run the same distance. But you can’t let your opponent define your own race, says GB veteran captain Christian Malcolm, who lines up against the Jamaican in the longer sprint next Saturday. Malcolm has seen sprinters come and go. And Bolt, he says, is no different.

“At the moment – he’s not 100 per cent fit and a lot of athletes know that. The key is you have your own plan. Don’t fear him. He may not start well. You just cant focus on him. You have to be ready because anything can happen.”