Jamaican sprinter Asafa Powell withdrew on Thursday from the men's 100-meter dash with an injury at the upcoming World Championships in Athletics here, his agency said. "Powell suffered a groin strain in Budapest on July 30 and has had recurring tightness and pain ever since," his representatives, Doyle Management, said in a statement on the website of the International Association of Athletics Federations (IAAF). "He has received all sorts of treatments over the past two weeks in the hope of being prepared to run the 100 ?eter here in Daegu but today Asafa made the final decision not to run. He feels he would not be at 100 percent and may have trouble coming back after each round."    Powell, the former 100 ?eter world record holder and the world bronze medalist in 2007 and 2009, owns the fastest 100 ?eter time this year at 9.78 seconds.