China's former Olympic 110-meter hurdle champion Liu Xiang on Monday headed to the world indoor championships in Doha, and his coach Sun Haiping kept a low key about Liu's performance.

Liu, who is making his comeback from Achilles tendon surgery, is slated to face reigning Olympic champion Dayron Robles of Cuba in the 60m hurdles at the world indoor championships in Doha from March 12-14.

"He is not in form. Don't have too high expectations for him," said Sun. "Our goal is to make to the final."

It will be Liu's second top-level meet since his injury. He finished second to American Terrence Trammell in the 110m hurdles at the Shanghai Grand Prix in September last year.

At the 2004 Athens Games, Liu became the first Chinese man ever to win an Olympic track gold medal. But he disappointed fans when he pulled out in a preliminary heat at the 2008 Beijing Olympics.

During a Chinese team competition in Shanghai at the end of last month, Liu posted a time of 8.05 seconds in the 60m hurdles, well off the world record of 7.3 seconds.