Liu pulled out of the 110m hurdles first round at the Beijing Olympic Games last month, citing a recurrence of the chronic inflammation in his Achilles' tendon.

As reported by Yangtse Evening Post, Liu may have to undergo surgery in the United States after Sept 20 and said it is hard to decide exactly how long the recovery will take.

After the conclusion of the Beijing Games, Liu and his coach Sun Haiping returned to his hometown of Shanghai last Friday.

Having a one-day rest at home, Liu returned to his training base in Shanghai for upper body training and healing of the injury.

Currently, the 25-year-old is undergoing examination by domestic experts and he will not seek for further treatment in the US unless his injury is in stable condition.

A doctor, who conducted the initial examination, told the Shanghai Evening Post that it will take about one year for Liu to get fully fit.

"My foot is not as swollen but I still cannot run," Liu was quoted by Liberation Daily of Shanghai. "When I tried to exert strength I could feel great pain. After the swelling goes down the doctors will work out a plan to perform a radical cure. I will continue training my upper body and remain optimistic."

Considered the biggest track and field star at the Beijing Games, the defending champion withdrew from his race, causing great surprise and disappointment for his fans.

Despite pressure from the public and watching rival Cuban Dayron Robles grab Olympic gold medal so easily, Liu has stayed calm and vows to return stronger than ever.

"I am not upset after watching the final race," he said in his column in the Liberation Daily after the finals of the Olympic men's 110m hurdles. "On the contrary, I still feel the desire for victory burning. I am still young. I have the potential. I can fight on against him (Robles)."

His coach said he will not push Liu to train unless he fully recovers .

"We will resume normal training when the doctors confirm that he has fully recovered. Liu is young and still at the peak of his career. I believe he will regain his best form."