World champion sprinter Tyson Gay has a mild strain in a muscle in the back of his leg and he has been told to restrict himself to light physical activity for the next two weeks.

Gay pulled up abruptly in the first 40 metres of his 200-metre qualifying race Saturday at US Olympic athletics trials. He had to be carted off the track. He was diagnosed with a severe cramp in his hamstring and an MRI that afternoon revealed the strain.

Engage in 'active rest'

A statement from his representatives said yesterday he is "expected to engage in 'active rest' for up to 12-14 days, with light physical activity increasing through that period, then resume training."

The only meet he is signed up for before the Olympics is the 100 metres at the London Grand Prix on July 24-25.

Gay, the defending world champion in the 100 and 200, already had qualified for the Olympic 100 metres. That competition begins August 15 in Beijing. If he can run, he also would be expected to be part of the 400-metre relay team.

But his chances for a medal in the 200 is gone because of the injury. USA Track and Field rules state that only the top three finishers in an event qualify for the Olympics, regardless of a runner's past record or any injuries.