Moscow: Heading into the world championships, Usain Bolt stands tall as ever while the sport around him has diminished.

It was always going to be a stretch for Bolt to match his exuberance and mass appeal from the London Olympics. But now the burden to carry his sport grows even more following a startling array of no-shows and doping scandals that has hit track and field hard.

Bolt is in a prime spot to add to his haul of gold medals. Of the sprinters who will be in Moscow for the championships, which open today, he has the fastest times in the 100 and 200 metres. And given Jamaica’s strength in the 4x100 relay, he is favoured for another golden triple.

Bolt won three golds at the 2008 Beijing Olympics, three at the London Games and three more at the 2009 worlds in Berlin. And with seven world championship medals already, a triple of any colour would also move him alongside American great Carl Lewis as the man with the most medals in the event’s history, with 10 overall.

“Right now, my only focus is winning three gold medals,” Bolt said in an email exchange with The Associated Press.

Only a year ago, Jamaican teammate Yohan Blake was challenging Bolt for Olympic supremacy in London, but came up with silver. This year was supposed to give him another shot, but the sprinter who won the world title in Daegu, South Korea, two years ago after Bolt false-started is out with a hamstring injury.

In Blake’s absence, a revitalised Tyson Gay was to challenge hard. Yet even though the American has the two top times over the 100 this year, Gay’s year, and perhaps his career, came crashing down when he relinquished his US sprint spots for Moscow after failing an out-of-competition doping test.

Almost at the same time, it was announced that former world-record holder Asafa Powell tested positive for the stimulant oxilofrone at the Jamaican national championships in June.

The scandals leave Justin Gatlin as Bolt’s toughest competitor in the worlds’ premier event. The 2004 Olympic champion already beat the Jamaican at the Diamond League meet in Rome this spring, Bolt’s only competitive flaw this season.

“He knows that I’m going to come with my ‘A’ and he’s going to come with his ‘A’ game,” Gatlin said. “We’re both the kind of people that turn it on when the lights come on in a competition.”

In his favourite race, the 200, Bolt is going for his third straight world title. His competition will be as much the clock as teammate Warren Weir. Bolt set the world record of 19.19 seconds at the 2009 worlds, but still feels he can improve.

“The 200 world record would be the one I’d really love to break again, to see if it’s maybe even possible to get it under 19 seconds,” Bolt said.

And when Bolt sets himself a challenge, he all too often turns it into reality.

The London Olympics still had plenty of world records, and none of the four was bigger than David Rudisha’s gold rush in the 800. The Kenyan, however, has seen his season go to waste because of a knee injury, robbing the championships of another big star.

Olympic heptathlon champion Jessica Ennis-Hill is also a no-show because of an Achilles tendon problem. And the local crowd won’t even be able to shout for the defending champion, Tatyana Chernova, since she, too, is injured.

Even off the track, drugs aside, the sport has been reeling. Besides Bolt, no track athlete quite sparked the London Games like Oscar Pistorius. The double amputee South African enthralled the 80,000-seat capacity crowds, proving that competing can be as important as winning. One year later, Pistorius is preparing for his murder trial in the Valentine Day’s shooting death of his girlfriend, Reeva Steenkamp.

“I don’t ever remember going into a world championships with this sort of, I don’t want to say doldrums, but I’d be lying if I said we have the normal anticipation and hype going into the worlds,” said four-time Olympic medallist and commentator Ato Boldon.

Besides Bolt, Mo Farah will be going for multiple gold. After he clinched the long-distance double at the London Games, he is a favourite to repeat the 5,000-10,000 double at the Luzhniki Stadium.

While the established stars are not there, it is also time for fresh faces.

At 24, Blessing Okagbare is hardly new, but Moscow could well become her breakthrough. The Nigerian has been strong in the sprints and long jump and, having beaten top challengers in all three events this year, she could be going for a triple gold.

Also look for Brianna Rollins, the 21-year-old hurdler. She became the third-best performer in history in the 100 hurdles when she ran an American record of 12.26 at the US championships in the fastest time in 21 years.

Not only does it underscore the potential for a world record at the championships, it also shows that, even with much new blood in the team, the United States looks set to dominate again.