China's Liu has inflamed Achilles - coach Sun

China's 110m hurdles defending champion Liu Xiang is suffering from an inflamed Achilles tendon, which may affect his running at the Olympics, his coach said on Sunday.

Liu, the hosts' main hope of a track gold who gets his campaign underway in the heats on Monday, felt sore during his final training session on Saturday and the cause was later diagnosed as tendon inflammation, Sun Haiping said.

"What I am really worrying about is the final," Sun told Liu's official web site.

If Liu safely makes it through the first three rounds, he is likely in the final to race Cuban Dayron Robles, who broke Liu's world record in June.

"In the final Liu has to strive with all effort and when he uses the force from the foot, the pain gets worse," Sun said. "It will definitely affect his performance."

A hamstring injury caused the world champion to pull out of a meeting in New York and he followed that with a disqualification at the Prefontaine Classic for a false start.

Liu, 25, has made few international appearances since winning the world indoor title in February.

"We will just hang around the Olympic village and tomorrow and co-operate with the experts' treatment," he said.