Liu Xiang's back injury which forced him out of Saturday night's London Diamond League final will not affect his chance of winning at the Olympic Games in three weeks time, his coach Sun Haiping said on Saturday.

"It's just a slight problem. Liu Xiang felt a little uncomfortable in his back after the heat round. We decided to pull out of the finals just for the sake of caution," Sun said, adding that after a night's rest Liu has felt very well.

"Liu Xiang could have finished the race if we wanted him to. But we thought that it was unnecessary in this event," Sun said.

"He will be sure to fight to the end in the Olympic Games," he added.

To avoid the wet and cold English weather, Liu and his team is reportedly to have left England for training. But Sun declined to reveal where they will be going.

Liu had cruised into the 110m hurdles final after winning his heat in 13.27 seconds but failed to take his place on the start line for the final for the injury.

Merritt defied the cool, overcast conditions to equal his own season's fastest time of 12.93 seconds. Richardson was second in 13.06 and another American Ryan Wilson third in 13.18.

"I will be back for the Olympic Games," Liu told Chinese reporters before boarding a coach for the Heathrow Airport.

The men's 110m hurdles at the Olympic Games will be held on August 7 and the gold medal be decided on August 8.