Gay pulls out of London clash

World 100 metres champion Tyson Gay has pulled out of his eagerly-anticipated head-to-head with Asafa Powell at the Aviva London Grand Prix on Friday night.

The American has lost his battle to regain full fitness following a hamstring injury.

The clash between Gay and Jamaica's former world record holder was set to one of the highlights of the meeting, but Gay had to accept tonight he must get his priorities in order with the Olympic Games on the horizon.

After winning the 100m at the USA Olympic trials, Gay then fell to the track in his 200m quarter-final on July 5 clutching his left hamstring, and an MRI scan showed a mild strain in the semi tendinosus muscle.

The injury was later diagnosed as more serious and two weeks ago, Gay flew to Munich for treatment from one of the world's leading sports specialists, Dr Hans-Wilhelm Muller-Wohlfahrt.

His management and medical team advised Gay, despite his eagerness to fulfil his commitment at the Crystal Palace meeting, a further setback could wreck his chances of competing in the fast-approaching Beijing Olympics.

The latest MRI taken on Monday, and discussed at a medical appointment this afternoon, showed Gay's hamstring strain to be healing well.

Mark Wetmore, the sprinter's agent, insisted: "The decision does not affect Gay's plans for Beijing, by which time he is expected to be fully recovered."

Gay is still undergoing treatment in Germany, and said: "I was really looking forward to getting back on the track again, and training has been going well.

"I held out hope to run London, but progress has been steady and with the first round of the Olympic 100 metres just three weeks away, I don't want to risk doing anything to set things back."