By Gene Cherry
DAEGU, South Korea (Reuters) - Jamaican former world record holder Asafa Powell pulled out of the world championships 100 metres with a groin strain Thursday, spoiling a highly anticipated showdown with current title holder Usain Bolt.
"Asafa is very disappointed to say the least," his agent Paul Doyle said in a statement. "He was really hoping to be able to run."
The world bronze medalist had the year's fastest time, 9.78 seconds, and many were giving him a solid chance of upsetting compatriot Bolt, the Olympic and world champion who has yet to hit top form this season.
Doyle said Powell still hoped to run the 4x100 meters relay.
The 28-year-old injured his groin in Budapest in late July and has experienced recurring tightness and pain ever since.
Powell, who missed the London Diamond League meeting with the injury, made the final decision not to run in Daegu on Thursday, Doyle said.
"He feels he would not be at 100 percent, and may have trouble coming back after each round," his agent said.
The withdrawal means the 100 meters, always the most glamorous event of the championships which start Saturday, will be without the two sprinters who shared the podium with Bolt in the 2009 worlds in Berlin.
Silver medalist Tyson Gay, the world's second fastest man, did not make the American team because of injuries.
Two other top sprinters this year - Jamaican Steve Mullings and American Mike Rodgers - will miss the championships because of doping violations.
With all the absences, Trinidadian Olympic silver medalist Richard Thompson, Jamaican Michael Frater and U.S. Olympic bronze medalist Walter Dix become Bolt's biggest challengers.
It was Frater, who broke the news of Powell's withdrawal.
"I didn't come here expecting to run the 100 meters but unfortunately Asafa couldn't make it," Frater told a Jamaican news conference before Doyle confirmed Powell's withdrawal.
(Editing by Justin Palmer)