** FILE ** Justin Gatlin of the United States competes in the Men's 100-meter event at the Qatar Grand Prix in Doha, Qatar in this May 12, 2006 file photo. The 100-meter gold medalist at the Athens Olympics, who hopes to run in the 2008 Beijing Games, tested positive for testosterone and other steroids last April but has said he doesn't know how steroids got into his system. The top assistant to track coach Trevor Graham gave Justin Gatlin an injection, which he believed to be vitamin B12, two weeks before the world record-sharing sprinter tested positive for steroids. (AP Photo)