LONDON, England (AFP) — Top US sprinter Tyson Gay said yesterday that winning an elusive, first Olympic medal was the missing piece of his heart.

Gay saw his Olympic dream shattered in 2008 by a hamstring injury and now the former World champion comes to the London Games after needing nearly a year to recover from right hip surgery.

"It's a lot of pressure, I'm not going to lie. The missing piece in my heart is an Olympic medal," said Gay, who will turn 30 four days after the 100m final on Sunday.

"It's really special to come here and compete for a medal. I came up short in 2008.

"Now I'm fully focused on these Games, and not my age or 2016, to leave with a medal."

But Gay acknowledged that he would be up against it in the blue ribbon event of track and field, and arguably the whole Olympics.

Rivals include the formidable Jamaican trio of defending champion and world record holder Usain Bolt, world champion Yohan Blake and Asafa Powell, as well as US teammate Justin Gatlin, the 2004 Olympic gold medallist.

"I know what those guys bring to the table and they know what I bring to the table," Gay said.

"Regardless of any radar, we're going to have eight finalists most of whom are capable of getting a medal."

Gay said he had nothing to hide, as shown by a rare open training session at the US camp in Birmingham, central England, last week.

"It is what it is. We're going to run this weekend, and that's it. I have nothing to hide."

Gay, who said his confidence was good and was undergoing "consistent treatment" on his hip and legs, also expected a fast time, but was quick to play down suggestions that Bolt seemed off the boil.

"I definitely think that's possible, if the weather holds and everyone's fit," he said of a fast time.

"I don't want to say Bolt's vulnerable because he's definitely proved that he can run 9.5, 9.6, 9.7sec.

"He's the only guy who has been where we others haven't.

"He has to be one of the favourites because he knows what to do to win competitions.

"My only hope is that my body's ready to go there (fast times) as well."

Turning to Blake, Gay said: "I remember running against Blake in London several years ago when he was just out of high school. He's definitely matured into a great young man running a professional sport."

Gay said he was not overly concerned with the prospect of having to race three rounds before even dreaming of the final, despite only having made his competitive comeback after 50 weeks on the sidelines in June.

"I'm not worried about it too much. I'll focus on executing my programme and I think I'll be okay," he said, warning that it was time the Americans regained sprint supremacy from the Jamaicans.

"It's very important for the US to try to get back on top in the sprints," he said.