Jamaica's Asafa Powell has been ruled out of the 100 metres at the World Athletics Championships, a teammate said on Thursday.
Michael Frater said he was replacing the sprinter in the blue riband race, but Jamaican team officials refused to confirm the news.
Earlier this month Powell withdrew from a race at Crystal Palace citing a groin injury.
Jamaican team leader Grace Jackson would not confirm Powell was missing the race, saying a "technical meeting" was taking place.
Clearly the news was not known even in sprinting circles. World and Olympic champion Usain Bolt said: "Asafa's out? That's the first I heard of it."
Powell's absence will take much of the lustre off the 100 metres race with Bolt now a standout favourite to retain his title on Sunday in the South Korean city of Daegu.
Former world record holder Powell is the quickest man in the world over 100m this year, having clocked 9.78 in Lausanne in June.