BRUSSELS: World champion Tyson Gay has pulled out of Friday's eagerly-awaited Golden League 100m showdown with Olympic champion, and world record holder, Usain Bolt and Asafa Powell, organiser Wilfried Meert said.

After training on Thursday, American Gay, who has been dogged by hamstring troubles which sabotaged his Olympic Games dream in Beijing where he failed to make the final, said he withdrew as he didn't want to risk further damage.

Gay, who had been due to face the two fastest men in the world for the first time in a 100m race, suffered his injury at the US Olympic trials in July and has yet to fully recover.

The 26-year-old now intends to focus on his preparations for defending his 100m, 200m and 4x100m titles at the 2009 world championships in Berlin.