The fast-talking 100m Olympic champion tells Duncan Mackay about his desperate fight back from injury, his lost aura of invincibility - and that he doesn't run away from drug testers

Maurice Greene owns the personalised number plate MO GOLD, but last year his rivals joked it should be changed to “Slow Mo” because the American seemed unable to find anything other than reverse gear. Here in Athens, however, five days before the final of the 100 metres, Greene believes he will have the last laugh on his critics by retaining his Olympic sprint crown.

“Athens is a great place for me,” he explains. “It is my second home. It's where I won my first world championship medal [in 1997], it's where I set my world record [9.79sec in 1999] and it's where a package is waiting for me that I've got to pick up. It's a little gold medal that says Athens 2004 Olympic Games, and it's got Maurice Greene and my time on there.”

After two years of injury and defeat and having recently turned 30, Greene is no longer the unstoppable force he was. He recently suffered consecutive defeats by the 21-year-old Jamaican Asafa Powell in London and Zurich, but dismisses them as irrelevant.

“It doesn't mean anything,” he maintains. “Just as if I'd won the races by 20 metres, it wouldn't have meant anything. It doesn't matter what you do before the games. It doesn't matter what you do after. It only matters what you do on the two days of competition.”

He also claims to be close to his 2000 form and perhaps even better, judging by the times he has clocked in training. He wishes his competitors luck. “I think now they're saying, 'OK, he's back, let's try to get him now.' I say, 'Bring it on.'”

In May he ran 9.78sec in California, which would have equalled Montgomery's world record had the effort not been wind-aided. He took off his spikes and (as scripted) his friend, the hurdler Larry Wade, rushed on to the track to douse them with a fire extinguisher. Next weekend, Greene's target is not only another Olympic gold but regaining the record from Montgomery, who achieved his mark by one-hundredth of a second in a just-legal wind of 2.0 metres a second. “He's the luckiest man in the world,” Greene has said.

But now that the United States Anti-Doping Agency has charged Montgomery with doping violations, Greene has reconsidered his position on his rival. Montgomery faces a lifetime ban from the sport because of his alleged involvement in the Bay Area Laboratory Co-Operative doping scandal, and finished only seventh in the US Olympic trials in July in 10.13sec - a race Greene won in 9.91.

But with so many Americans having been banned this year for failing drugs tests - 14 at the last count - and more implicated in the Balco scandal, there is a lot of scepticism surrounding the US team here.

“It's going to be very hard now to convince someone that what you're doing is pure,” Greene concedes. “I just tell them I have a God-given talent and I work very hard for what I do. Anybody can run fast. It's how you run fast. I pay attention to technical things now.”

Greene is confident he can break the world record in the Greek capital. “The world record will come to me when I run the world record race,” he says. “I'm just trying to perfect my race. I'm looking for perfection.”