Chinese hurdler Liu Xiang's return to competition has been delayed even further because of continuing problems with his injured foot, his coach said Tuesday.

Earlier this month, Liu's coach, Sun Haiping, told China's Daily newspaper that the hurdler was targeting a September return to competition. A recent medical check showed the Liu's recovery hadn't progressed as far as Sun would like.

"We feel satisfied about Liu's recovery and the medical check revealed that his tendon is getting better but it's not enough yet," Sun told the Xinhua News Agency. "He still needs time before coming back to competition."

After Liu earned China's first track and field Olympic gold medal at the 2004 Olympic Summer Games, an injury to his right foot prevented the hurdler from defending his 110-metre title at last summer's Beijing Games. Liu famously withdrew from the start line of the heats in front of his home crowd.

Liu began light training after surgery on the foot in December, but Sun announced earlier this year that the injured athlete would not attempt to defend his world championship title at the Berlin event in August.

"There's really no need to rush," Sun told a news conference in Shanghai. "It is immature for him to run in competitions at this moment. We can count Liu in when he is fully ready. If he injures his leg again, it will certainly end his career once and for all."

- With files from the Associated Press