Badminton world number one Lee Chong Wei has admitted his injury at the Thomas Cup in China this week is a blow to his Olympics title bid, where the Malaysian has a last shot at an elusive gold. "Injury like this can affect mental preparation," a tearful Lee said before flying back to Malaysia Wednesday to have a second MRI scan and treatment on his torn ankle tendon. "It is still painful... One has to be strong. I know I will be okay. I have to be stronger mentally to do well in the Olympics." The 29-year-old star shuttler landed awkwardly after going two points ahead in his group match against Denmark's Peter Gade. Doctors rushed onto court but the player was crying and in visible pain as he was taken away for scans and treatment at a nearby hospital. He is expected to be out for up to a month. The world team championships in Wuhan had been the last chance for Lee to go head-to-head with his arch-rival Lin Dan before the Olympics. "Our biggest enemy is not each other but injury," said China's world number two Lin, who took gold ahead of the Malaysian at the Beijing Olympics four years ago. At Athens in 2004 Lee was knocked out in the second round. "We are not so young any more and in the future injuries will happen more and more. We don't have so much time left," said the 28-year-old Lin, the game's most decorated player. "It is such a pity he is injured. He's my best friend and I hope he will recover quickly in time for the Games." It is the latest blow for the Malaysian, whose preparations have already been hampered by a shoulder problem, a bout of influenza and a series of disappointing results this season. At the India Open in April, Lee was stunned in the final by the unseeded South Korean Shon Wan-Ho, who beat him in a three-game, 66-minute thriller. That defeat came a month after Lee was forced to retire against Lin from the All-England Championships final. Just ahead of the Thomas Cup, Lee was struck with flu and unable to join his teammates for early training, but had looked fit and focused in his first group match against South Africa.