Ask some of track and field's most legendary sprinters who they expect to earn the title of World's Fastest Man on Sunday, and their responses may come as a surprise.
It's not the man who adorns billboards from Mexico City to Tokyo. It's the less publicized reigning world champion.
Jamaica's Yohan Blake is the pick of former Olympic gold medalist Maurice Greene to win the men's 100 meters over world-record holder Usain Bolt. Blake is also the favorite in four-time Olympic medalist Ato Boldon's eyes. And while 400 meters world-record holder Michael Johnson won't go so far as to predict Bolt to lose, he did recently label Blake a "legitimate challenger."
[ Video: Carl Lewis' predictions for U.S. men ]
The doubts about Bolt have emerged because he's not running at the superhuman level he did while shattering world records in the 100 and 200 meters in 2008 and 2009. He false-started at the World Championships last August, battled nagging back and hamstring injuries much of this year and was beaten by Blake at the Jamaican Olympic trials earlier this summer.
Bolt may yet regain his superhero form of a couple years ago and make everyone look silly for doubting him in London, but his struggles the past 12 months have infused track and field's signature race with unexpected drama. The London field includes five of the seven fastest men in history, so there is no shortage of sprinters capable of capitalizing if Bolt can't run away from the pack.
[ Athlete profile: Find out more about Usain Bolt ]
Blake has earned the right to be considered Bolt's top challenger after taking first place in his absence at the World Championships last year and beating him in a sizzling 9.75 seconds at the Jamaican trials in late June. This will be the 22-year-old's first big meet in which he's expected to medal, however, so he must prove that he can handle the pressure.
Besides Bolt and Blake, the Jamaicans have one more sprinter with legitimate aspirations of winning a medal. Enigmatic former world-record holder Asafa Powell consistently ran in the 9.7s and 9.8s a couple years ago, but injuries and an inability to finish big races strong have hampered him more recently.
Yohan Blake (Getty Images)The two sprinters most capable of breaking up a Jamaican sweep are Americans Tyson Gay and Justin Gatlin, both of whom believe they can medal and perhaps even challenge Bolt and Blake.
[ Memorable Moments:
Usain Bolt's wow moment ]
Gay, the 29-year-old injury-plagued former world-record holder, is still looking for the first Olympic medal of his career after failing to qualify for the 100 meters final in Beijing due to a hamstring injury. He insists he's fully healthy now, but he has yet to approach the 9.69 seconds he ran in 2009 in a Grand Prix event.
Gatlin, the Olympic champion in 2004, could be a better weapon against the Jamaicans than Gay for the U.S. because his speed out of the blocks gives him a chance to pressure Bolt and Blake into breaking form. Since returning from a two-year doping suspension last year, Gatlin has gradually regained his previous speed, running a personal-best 9.80 seconds in June to win the U.S. trials over Gay.
Between Bolt, Blake, Powell, Gay and Gatlin, there's more than enough star power to ensure high drama and fast times. The only question is if the notoriously dreary London weather will cooperate.
Sprinters like conditions to be as hot and dry as possible, but there's rain in the forecast in London this weekend. Hopefully the showers hold off, however, because that's the only thing that could jeopardize maybe the most anticipated races of the Olympics.
More Olympics coverage on Yahoo! Sports:
• Qatar runner's historic run comes to abrupt, heartbreaking end
• Photos: Will & Kate's Olympic PDA
• Swimming legend's odd retirement advice to Michael Phelps