By Mitch Phillips
LONDON (Reuters) - Justin Gatlin will run for the United States in Beijing but to much of the athletics world he might as well appear in a vest bearing a giant syringe such is his position as the tangible manifestation of the sport's wretched doping past.
There will be dozens of convicted former dopers in the world championships -- with the top end of the 100 meters riddled with them -- but Gatlin has a special place in the Hall of Shame by dint of being the man who has been banned twice.
In normal circumstances that second positive test -- in 2006 -- would have earned him a lifetime ban but after he agreed to co-operate with the anti-doping authorities that was cut to eight, and then four years.
People were certainly unimpressed when he returned to the track with sluggish performances but as his times fell, the opprobrium grew.
Now he will arrive in Beijing on the back of an astonishingly dominant run, all the more astonishing for the fact that he is 33 and running faster times than when he won the Olympic and world titles in 2004 and 2005.
Gatlin last tasted defeat over 100m in September 2013 and over 200 in May of the same year. Since then he is unbeaten in 27 races over both distances.
He has run the four fastest times of the year for the 100m, with a best of 9.74, and the two fastest 200s, peaking with 19.57 -- both personal bests and his 100m time the best in the world for nearly three years.
That all means he has a real chance of beating defending champion Usain Bolt, who is racing against time to regain his best form after a hip injury.
Their meetings will be the most anticipated races of the championships and Gatlin, who has won only one of their seven 100m head-to-heads, is as excited about them as the fans.
"Hopefully the Beijing 100m or 200m finals will be the right time for us to be able to put on a spectacular show," he said recently. "It's a great lead up to a really good story."
Gatlin still refuses to consider himself a doper, arguing that his first positive test for a stimulant was a result of medication he had been using for years and maintaining that his second came through a rogue masseur rubbing testosterone cream into his legs.
He does say though that it was the bans and his subsequent time away from the track that have given him longevity as he now feels "26 or 27 years old".
Cheat or victim, Gatlin will nevertheless be widely perceived as the cowboy in black when he faces down Bolt, held by many to be the shining beacon of hope in a drug-ravaged sport.
"At the end of the day I have to get on the line, I have to get out there and cross the finish line first and that's my job," says Gatlin.
"What the critics say about me doesn't really bother me."
(Editing by Sudipto Ganguly)