Glen Mills appears remarkably calm for a man who must soon decide whether to assume the mantle of the biggest party-pooper in sport. After four years spent debating costs, scandals, builders, Tibet and tumbleweed, not to mention the madness of an event that deems it necessary to deliver new, mange-free pandas to Beijing Zoo, the world has Olympic fever. And it wants to see Usain Bolt run the 100 metres.

Mills is the sprinter’s coach and is nonplussed. The white beard hints at a sagacity that cuts through much of the emotional hype surrounding athletics. So he explains bluntly that he could have “saved” Dwain Chambers had he got hold of him earlier and that Bolt would be hounded out of Jamaica if he tested positive. For Mills, sport has a simplicity that makes it sacred.

“I remember some robbers got on a bus and they had guns,” he said. “Then they realised there were athletes on board. It was, like, ‘Er, sorry.’ It’s not that people are honest. They will stick you up or forge cheques, but people love and respect sport here.”

Bolt is the 21-year-old 200 metres specialist who was second at last year’s World Championships. This season he started racing over 100 metres to build up his speed, but then he lowered the world record to 9.72sec and the subplot went to pot. Bolt has said that he will skip the 100 metres in Beijing if Mills wants him to, but the absence of the world record-holder would devalue the blue-riband event.

“I said at the start of the year that we’d practise the 100 metres and, if he got as fast as everyone in the 200 metres, then maybe we’d run both at the World Championships next year,” Mills said. “But the 100 took off like a rollercoaster.”

So what is the problem? Is this just a bit of kidology, or is he serious about barring Bolt from taking on Asafa Powell, his compatriot, and Tyson Gay, the American, who will miss the 200 metres in Beijing after pulling up in the United States trials?

“In the 100 metres, you need to be very experienced,” Mills said. “In Stockholm last week, Usain was left at the start and just got up and ran, abandoning all his technique. The 200 metres is his comfort zone and it’s a much easier race for him. There is a temptation to take what you’re sure of. We’ve run the fastest times in both races this year, but they are one-offs and the Olympics is about four races. There are things we need to master in the 100 metres.”

It is a noble sentiment in some ways because Mills’s stock would rise through the roof if he took Bolt to an Olympic double. Having started coaching at 14 and received Jamaica’s Order of Distinction, he is a father figure to Bolt and believes that he might have served the same function had he worked with Chambers before his drugs-taking.

When Chambers was first on the comeback trail in 2005, having served a two-year ban imposed by the IAAF, Mills helped him. He is one of the few to stand in the middle ground of the moral quagmire that engulfed Chambers’s bid to overturn his life ban from the Olympics. “People who take drugs should not be allowed to take part in sport,” Mills said. “But I believe in natural justice and what’s happened to Dwain is not that. The IOC allows people who have taken drugs to come back, but Dwain can’t. It’s hypocrisy. Britain should not allow anyone into the country if they’ve taken drugs.”

Torri Edwards, an American sprinter whose doping ban was reduced to a year after the World AntiDoping Agency downgraded nikethamide, was invited to the Aviva London Grand Prix in Crystal Palace last weekend; Chambers was not.

“He could have been great,” Mills said of Chambers. “When he came to Jamaica [in 2005] I felt, if he’d been coached properly he would have been one of the best in the world. What was wrong? His start, the transition, his ability to get to top speed, standing up too early.”

Mills believes that Chambers required a mentor, such as Bolt had in Norman Peart, his manager, who has been with him since high school. “Dwain needed a guardian angel,” Mills said. “Some young athletes are naive or easily influenced or not very bright. They rely on others. Why did he go with that coach [Remi Korchemny] with that background? Everybody had known for years that side of the world was bad news.”

The taint of suspicion also affects Jamaica, which does not have an antidoping federation and relies on importing IAAF testers. Mills says that the only Jamaicans who have got into trouble were those who left for other countries, although a day after we spoke, the Jamaica Olympic Association confirmed that an athlete had failed a test. “If Usain tested positive, he would have a miserable life,” Mills said. “Jamaica’s a violent place and people would force him to leave. In the past we have suffered because of others who have been on drugs. It’s painful, but we believe we are talented enough.”

Bolt certainly is, but Mills said that he has two weeks before he must declare his hand over the 100 metres. He will not be swayed by sponsors, the public or by Bolt. Part of the sprinter’s mental conditioning involves debating issues with his coach and backing it up with reasoned points. “I’ve beaten him twice in five years,” Bolt said. He knows that this is an argument that he will not win and so, like the rest of the world, he waits and hopes.