"I don't want to sound rude, but Gatlin's had his chance," Usain Bolt

31 May,Usain Bolt has dismissed suggestions former Olympic champion Justin Gatlin will provide the biggest challenge for his 100m crown at London 2012.

Gatlin, who won 2004 gold in Athens before a four-year drugs ban,clocked 9.87 seconds in Doha two weeks ago.

"I don't want to sound rude, but Gatlin's had his chance," said Bolt. "He's been on top, but to say 'get ready for the Gatlin show' is funny.

"He has a few guys to get past before he should be worried about me."

World indoor champion Gatlin staked his claim as a contender for the Olympic 100m with victory in Doha's Diamond League meeting on 11 May.

The 30-year-old aims to book his place at London when he runs in the United States team trials in Portland next month.

But Bolt, who won 100m gold in Beijing four years ago, believes American Tyson Gay and current World Championship title holder Yohan Blake will provide sterner challenges than Gatlin.

Meanwhile, the Jamaican sprinter has pledged to bounce back at Thursday's Diamond League meeting in Rome after his disappointing time in Ostrava last week.

He clocked 10.04s in last Friday's 100m and afterwards blamed a lack of sleep and food.

He said: "I explained to my coach that my legs were not feeling that energetic, probably through a lack of sleep and not enough food.

"I've been trying to get a lot more sleep and eating better."

Bolt's time in Ostrava was the first time since 2009 in Toronto that the Jamaican has failed to break 10 seconds in a final.

However, the triple Olympic champion was in relaxed mood ahead of this week's meeting in Rome and admitted he does not feel under pressure to perform in every race.

He said: "You never have a good race every time you run. You have to just put that behind you and move on. It's not a worry. I have a lot more races and the main one is at the Olympics.

"I have set a high standard for myself so I know people like to see me run fast.

"I can't look at it as pressure. People expect you to do certain things - I know I will have my bad races but I have to stay strong and focused."

Bolt will face fellow countryman and former world-record holder Asafa Powell, France's European champion Christophe Lemaitre and veteran Kim Collins in the 100m on Thursday.

Britain's world 400m hurdles champion Dai Greene faces a tough test in Rome, with American Bershawn Jackson among those keen for revenge after the Welshman's victory in Daegu last year.

There is British interest in the men's long jump with both Greg Rutherford - who set a world Long Jump lead of 8.35m in California at the beginning of May - and Chris Tomlinson in action, while Andrew Osagie and Michael Rimmer go in the 800m.