MOSCOW — Anytime Usain Bolt steps into the blocks he makes for compelling theater.

And track and field these days can use some drama that has nothing to do with drug tests. Doping scandals have left a cloud on the sport that Bolt can help lift with a run for gold at the world championships, which begin Saturday.

Track’s showcase event will be without plenty of headline names: Tyson Gay, Asafa Powell, Sherone Simpson and Veronica Campbell-Brown have recently tested positive for banned substances. Yohan Blake, Bolt’s top rival in the 100 meters and the defending champion, is out because of a hamstring injury.

Granted, in the best of circumstances, there aren’t many threats to Bolt in the 100. And about now the Jamaican’s biggest challenger may be the clock.

“After the 2012 Olympics, I was telling people who weren’t into track and field, `Hold onto your popcorn because next year is going to be even more exciting. We’re going to have the same people,”’ American sprinter Justin Gatlin said. “Never in a million years would I think it would end up like this. I still think it’s going to be exciting.”

In any case, it’s not as if Bolt won’t be pushed. After all, Gatlin beat him in Rome two months ago and is eager to show that wasn’t a fluke and he’s closing the gap on the world-record holder.

These two aren’t exactly best of friends. They don’t really talk much off the track, but there’s definitely a measure of respect. Hard not to respect the sprinter who has captured six Olympic titles and shattered world records in the 100 (his current mark is 9.58 seconds) and the 200 (19.19).

Blake fleetingly stole Bolt’s stage last year by beating his teammate in the 100 and 200 at the Olympic trials and by winning the world 100 title in 2011 when Bolt false-started.

Had Blake been healthy, this would have been a good rematch. Gay would have been a worthy opponent, too, especially since he was healthy for the first time in quite a while. But the American, who won the 100 and 200 at nationals, failed an out-of-competition doping test.