Sun Haiping, the coach of Liu Xiang, can look back now with relief and state the star hurdler's comeback from a serious leg injury was nothing short of a "miracle".

China's star hurdler, Liu Xiang, acknowledges fans at the Hong Kong International Airport yesterday. Liu will compete in the 110m hurdles at the East Asian Games tomorrow. Edmond Tang

Liu returned to the track after 13 months away from the sport at September's IAAF Golden Grand Prix in Shanghai and finished a stunning second. He then went on to win at the National Games in Shandong and Asian Championships in Guangdong.

"Many athletes have not been able to make it back to the track after injuring their Achilles tendon," Sun said.

"Some doctors and experts from Shanghai were gloomy about Liu's injury at the beginning but now they are amazed by his convalescence, which was comparatively short and the recovery has been almost perfect," he told China Daily yesterday.

"It's a miracle and even his American doctor said so."

Liu arrived in Hong Kong yesterday to compete in tomorrow's 110m hurdles at the East Asian Games.

Four days ago, in Shanghai, he was checked by Tom Clanton, the American doctor who performed the surgery on his injured right foot last year, and was given a clean bill of health.

As usual, Sun remains wary of pushing his star to hard despite the positive result.

"It is not, as some reports indicate, that Liu has totally recovered. I would say he is at most 90 percent," he said.

"And we are very concerned about the other 10 percent, which I believe is crucial."

Because of that caution, Sun said he did not want to impose intensive training on Liu just yet.

He said he wants to build up the Olympic and world champion gradually on the way to ultimately regaining his world-beating form .

"I have to be very careful with the workload on him as the ankle is still vulnerable," said Sun.

Liu has not missed a day of training since the Asian Athletics Championships in Guangzhou last month. He cruised to victory there in 13.50 seconds. In Hong Kong, Sun expects Liu to run about 13.40.

Sun said although Liu's confidence is high following his successful comeback performances, the athlete remains wary of a recurrence of the injury.

"Liu didn't want to miss the East Asian Games and he was doing everything he could to prevent getting hurt again. He is very confident of victory in Hong Kong this Friday," said Sun.

The men's 110m hurdles preliminaries at the Games are scheduled for 9:40 am tomorrow and the final is set for 3:30 pm.