European and Commonwealth 400m hurdles champion Dai Greene is "perfectly fit" despite withdrawing from Saturday's London Grand Prix at Crystal Palace.
Greene has recovered from a virus but wants to focus on training for the World Championships in South Korea, which start on 27 August.
"For all those asking, I am no longer running at Palace on the weekend," the Welshman said on Twitter.
"[I] want to concentrate on training ahead of Daegu"
Greene, who competed in the 400m flat event at the British trials in Birmingham last weekend, will travel to South Korea hoping to add world glory to the Commonwealth and European crowns he won in 2010.
But Greene was beaten into third in Monaco last month - behind Angelo Taylor and Bershawn Jackson - where he admitted feeling "run down" as he "struggled to get to top speed."
Greene added on Twitter: "I am not ill.
"Just want to do two weeks of hard training before I head to Korea, won't be able to train much when there."
Coach Malcolm Arnold insists there is no concern about Great Britain's number one hurdler aiming to improve on his seventh place at the 2009 World Championships in Berlin.
"There are no issues about his fitness, he's fine," Arnold told BBC Sport.
"He is perfectly fit and we're spending time trying to make him fitter in the next couple of weeks ahead of going to Daegu on 15 August."