China's Liu Xiang will probably not defend his world 110m hurdles title in Berlin later this year because of the injury that forced him out of the Beijing Olympics, his coach told local media yesterday.

The 25-year-old former world record holder and Olympic champion had surgery on the injured foot last month but will not be back in competitive form in time for the Aug. 15-23 World Championships, Sun Haiping told Titan Sports.

"Liu will not attend the worlds unless he is able to run at least 13.20 seconds before that, otherwise it makes no sense for us to go to Berlin," said Sun.

"That is likely to be too difficult for him. He might be eliminated after the first heat and that would be terribly damaging to his confidence."

The Athens Olympic gold medallist Liu was robbed of the chance of defending his title on home soil last August by the Achilles' injury.

He has been away from the track since his dramatic departure from the Bird's Nest stadium on Aug. 18 and is currently undergoing rehabilitation in the US.

Liu could be back in training as early as April, but the highly competitive World Championships need at least half a year to prepare for, Sun said.

"He will probably return to competitive running at the Shanghai Grand Prix in September," he said. "Our key target is the London Olympics."

Cuban Dayron Robles, who took the world record and Olympic title away from Liu last year, will be favourite to win his first 110 metres hurdles world title in Berlin.

He finished fourth behind Liu in Osaka in 2007.