THEY PRINTED up the heat draw for the men's 100 metres last night, a timely reminder the headline act was about to take to the main stage. If this isn't one of the most anticipated sprint showdowns in Olympic history then the world's fastest man must be hiding out somewhere in Tibet.

Heat 1:Usain Bolt; Heat 2:Asafa Powell; Heat 5:Tyson Gay.

The three fastest 100-metre runners of all time, kept apart, for now, as the track-and-field events finally get underway in the Bird's Nest tomorrow morning.

Come Saturday evening, all three will surely meet in the same race for the first time, and with that comes a show of fireworks set to rival the Opening Ceremony.

No one, however, is overlooking the fact that the one big name missing is the defending Olympic champion. Two years after he won the title in Athens, Justin Gatlin failed a second drugs test, and for that the American is serving an eight-year ban.

He joins the infamous company of Ben Johnson, who did more damage to the credibility of the Olympic 100 metres than any other sprinter by testing positive in 1988 in Seoul, and also Linford Christie, who for years boasted about being "clean" when winning in 1992 in Barcelona, only to later test positive for steroids.

Now more than ever the Olympic 100 metres is on a life-support machine, and there's no way it can survive another major drugs scandal. No one knows that better than the International Olympic Committee (IOC), and they're taking absolutely no chances this time.

Since the Jamaican athletes moved into the Athletes Village at the weekend, including Bolt and Powell, they've been subjected to 32 blood and urine tests, and their chef de mission, Don Anderson, is not particularly impressed. Powell is even claiming he's given so much blood over the past five days that it could well impact on his performance.

"We are concerned that this could have a serious effect on our athletes," said Anderson, who added that some of his athletes have been tested three times in five days. "We feel there has been an exceedingly long list of tests and we find this extremely unusual.

"There is certainly far more testing, but the only concern to us is they have taken a lot of blood. This is not a protest but we are just saying that it is rather unusual."

An IOC spokeswoman, Giselle Davies, said the total number of tests had been intentionally increased, from about 3,500 in Athens four years ago to a target of 4,500 in Beijing.

"We have a very comprehensive doping programme," said Davies, adding that around 1,500 tests had already been done. "If athletes have any concerns they should raise them with the authorities."

It is well known Jamaica has been slow to implement a strict national anti-doping code, and while their athletes are randomly tested by the IAAF, they wouldn't be used to the scale of testing going on in Beijing.

Nor would they be alone; few if any of the African nations have a strict anti-doping code either, and even the American system has been proven to have its faults.

Powell has always been adamant about the need to rid the sport of drugs, describing cheaters as criminals and insisting the best way to tackle the problem was to test more frequently.

"I accept how important it is, but they're really down on my case," he said. "I got pretty upset two days ago because since I have been here, they have tested me four times. They've taken so much blood from us we're going to be very weak before the final."

Bolt reports being tested dozens of times since lowering the world record to 9.72 seconds in New York at the start of the season, and the IAAF do demand extremely strict doping controls before they ratify any world record.

Gay, meanwhile, is one of 12 members of the US Olympic team to volunteer for extra blood and urine testing, as part of a "Project Believe" campaign towards drug-free sport. Speaking in Beijing, he reiterated his support for that cause: "I understand that because past champions tested positive for drugs, the Olympic champion does have to be clean and then to be able to prove it.

"People will always speculate about drugs and they know what I'm doing in the US, where I'm getting drug-tested a lot. That's to show my love of the sport."

Yet in some ways, the Bolt-Powell-Gay trio have already distanced themselves from the tainted past of Johnson-Christie-Gatlin. None of them go around with the sort of inflated egos and ferocious eyeballing more appropriate to heavyweight boxing.

Powell and Bolt describe their rivalry in almost cuddly terms, not just because they're from the same country. "Every day we have been together here, he (Bolt) called me The Fast Man and I called him Sarge," said Powell. "We have been friends a long time and nothing changes us."

Gay's humbleness has always been particularly evident, as demonstrated here when he met the basketball player Kobe Bryant in the US team gym. "I went up to him and asked if I could have my picture taken with him," recalled Gay. "And he said to me, 'How's your injured leg doing?' I had to text my mum - 'Kobe asked about my leg!' She was shocked as well. It was just amazing."

Maybe then this will be the cleanest Olympic 100 metres in a long time. For now, it's certainly the most anticipated.