Exactly when China's star hurdler Liu Xiang will return to competition remains a mystery as his injured right foot is still not yet ready for the wear and tear of sprinting.
"Liu will go for another check at the end of this month and if his foot is not completely cured, we won't let him train in spiked shoes and his return will be postponed," Liu's coach Sun Haiping, who said the injury was about 90 percent better, told China Daily.
"All of our efforts are to get Liu back to normal, so we won't push him hard to take part in competition," he added.
In this May 11, 2009 file photo, Chinese hurdler Liu Xiang shows quake zone pupils how to hurdle at a primary school in Beichuan county, southwest China's Sichuan province
The right foot injury forced the reigning world champion and former Olympic champion to withdraw from the Olympic Games men's 110m hurdles last August.
He had calcium deposits removed from his right Achilles' tendon last December before returning to China in March for further rehabilitation and preparation for competition.
Sun said he still did not know how long it would take for Liu to fully recover from the injury.
"Liu's recovery is well under way after the surgery and we are getting closer to his return step by step," Sun said. "The doctors are optimistic about his injury fully healing, but as a world-class athlete, he is different from other patients.
"According to the check on April 30, there is still a little hole in Liu's right heel, which was left after the removal of the spur.
"As a hurdler, when he does some special movements like hurdling, his heel still could not endure the heavy pressure right now. We still have to wait," Sun said.
Liu will train with spiked shoes and make his comeback to competition in September if his heel has recovered by the end of this month
"We hope Liu can run at the Shanghai Golden Grand Prix in September before taking part in his third National Games in October. No matter what kind of result he could achieve, we can show that Liu is back," Sun said.
"Liu has defended his titles in several competitions, such as the Grand Prix in Lausanne, Eugene and Osaka. He also expects to defend his National Games title for the third time in October.
"If he can achieve a time of 13.20 to 13.30 seconds, he will win the National Games. Such a result is not beyond him."
In 2006, Liu set a world record of 12.88 seconds at the super grand prix meeting in Lausanne.
The record was shaved by a hundredth of a second by Dayron Robles of Cuba two months before the Beijing Olympics.
"We expect to take part in the competition in September and are working toward it, although we cannot control how the recovery will develop," Sun added.