Tyson Gay is well aware that he not only runs for gold in the blue-riband 100 metres at the Beijing Olympics but also for the credibility of the sprint in general and the American team in particular. ( dpa )
"The Olympic champion does have to prove that he is clean," the three-time 2007 world champion said this week.
Ever since Ben Johnson was revealed to be a steroid cheater at the 1988 Games the world's fastest men have been met with suspicion.
World record holders have been caught and individuals and relay teams stripped of medals. When the 2004 Olympic champion Justin Gatlin, an outspoken advocate of clean sport, was also revealed using forbidden substances there was a crisis.
"It is a truly important time for us. We have accepted that," said US men's head coach Bubba Thornton, naming his athletes "ambassadors" at the Games in China.
Another positive test would be nothing but a disaster for the showcase sport of athletics which only recently had to swallow what appears to be a major tampering scheme involving Russian athletes.
The magnifying glass is on the sprint from Friday's heats to Saturday's big final where Gay meets Jamaican aces Usain Bolt (the world record holder) and Asafa Powell (the former record holder).
Gay named the Olympic race "one of the hottest 100m in history" but due to the tainted image nothing will be really clear until the mandatory drug test of the winner has returned - preferably negative.
Johnson was stripped of his gold and his formidable world record 9.79 seconds in the big Seoul drugs scandal.
Other offenders include the 1992 gold medallist Linford Christie (Britain, nandrolone, 1999) Dennis Mitchell (US, testosterone, 1998), Dwain Chambers (Britain, THG, 2004), former world record holder Tim Montgomery (US, various drugs, 2005) and the 2004 Olympic champion and former world record holder Justin Gatlin (US, testosterone, 2006).
Things don't look better on the women's front, with three-time 2000 gold medallist Marion Jones (US, THG, HGH, 1999-2001), two-time 1991 world champion Katrin Krabbe (Germany, clenbuterol, 1992), two-time 2003 world champion Kelli White (US, modafinil, 2003) and Torri Edwards (US, nikethamide, 2004) all caught.
Jones' fall was the most spectacular as she lost all her medals and is imprisoned over false testimony in connection with the Balco saga around the California laboratory and its designer drugs.
Coach Trevor Graham was the man who allowed doping testers to detect the wonderdrug THG when he anonymously passed on a sample, but he has long fallen from grace because too many of his athletes have been caught doping - including Jones and Montgomery.
Former 110m hurdles Greg Forster said the biggest challenge of the current generation of athletes was to prove that they are clean. He said the athletes realize that cheating is not worth it.
However, with Bolt (9.72), Powell (9.74) and Gay (9.77) running into a new dimension over the past months the suspicion will never die, with some already wondering out loud about the efficiency of drug testing in Jamaica.
Gay said boldly it would take a 9.6 time to beat Bolt but he was unable to answer how far the record can be lowered without the help of forbidden substances.
"I don't know if you have to dope for 9.6," said Gay.