Please, Usain, please be clean as drugs thunderbolt strikes down Tyson Gay and Asafa Powell Usain Bolt did the 'double double' in London, winning the 100m and 200m finals in consecutive Olympic Games. Picture: PA PLEASE, Usain, please. The future of track and field rests on your ability to say no, which sadly your two biggest threats have failed to do. Athletics sits on a fine line with its reputation because there have been too many cheats over its history. Within a matter of a couple of hours yesterday, it took two near-mortal blows with news that Tyson Gay and Asafa Powell had both tested positive a month before the world titles. Gay is a former world 100m champion who has run the three fastest times for the year and was seen as the man finally to topple Usain Bolt. Powell was everyone's good guy. The former 100m world record-holder has many friends in Australia and was here for the Stawell Gift three months ago. Now he's a cheat. And so is his training partner Sherone Simpson, an Olympic relay gold medallist, who also tested positive for the stimulant oxilophrine at last month's Jamaican titles. This comes weeks after two-time Olympic 200m champion Veronica Campbell-Brown was suspended by the Jamaican federation after a positive test to a banned diuretic. Bolt has done so much to bring the sport out of its drug shadow. When he smashed the 100m and 200m world records, the "is he or isn't he" question asked every time a male sprinter does something extraordinary wasn't really an issue. Asafa Powell was everyone's good guy. With many friends in Australia, he was here for the Stawell Gift three months ago. Even to the layman, it was obvious the Jamaican's freakish physical make-up was the reason behind his amazing speed. Bolt also made everyone feel good about the sport. Now the shadow is over him because of the Lance Armstrong precedent. While Lance said he was innocent, every single person who'd finished behind him in the Tour de France tested positive. So it begged the question: How could Armstrong not be a cheat? And we know what happened there. What makes Gay's positive test even more galling is the 30-year-old had promoted himself as a drug-free athlete. I don't have lies ... I basically put my trust in someone and I was let down," Gay said. Powell, 30, and Simpson, 28, were also blaming others with their physical trainer, who'd been providing them with supplements, detained by authorities in Italy. "I am not now, nor have I ever been, a cheat," Powell said. We've heard that line before somewhere. Think Lance. Bolt is good friends with Powell and the pair have run together in record-breaking relay teams. They have different training groups but with more Jamaican athletes said to have been caught, the world is now looking at Bolt in a different light. Please, Usain, be clean.