Liu Xiang's pullout from the final of the 110 metres hurdles at the London Grand Prix on Friday was just a precautionary measure and the back problem that forced the withdrawal does not pose any threat to his Olympic campaign, his coach said.
The 2004 Olympic champion, who turned 29 on Friday, pulled out of the final after tweaking his back while warming up but coach Sun Haiping said Liu was feeling well after a night's rest.
"It's just a slight problem. Liu Xiang felt a little uncomfortable in his back after the heat round. We decided to pull out of the finals just for the sake of caution," Sun was quoted as saying by the Xinhua news agency.
"Liu Xiang could have finished the race if we wanted him to. But we thought that it was unnecessary in this event.
"He will be sure to fight to the end in the Olympic Games."
One of China's highest-profile athletes, Liu won gold in Athens eight years ago but injury robbed him of the chance to defend his title on home soil in 2008.
"I will be back for the Olympic Games," Liu told Chinese reporters before leaving for an undisclosed training location, the report added.
Liu is a medal favourite at the Games but is likely to face stiff competition from Cuba's Olympic champion and world record holder Dayron Robles.