GLASGOW - Xie Xingfang, second only to Zhang Ning in world badminton women's singles ranking, still needed to improve her mental strength, her coach said.

Tang Xuehua, in charge of women's singles shuttlers of the Chinese team, told Xinhua on Monday that Xie was still not physically strong and needed more improvement on mental strength.

China's Xie Xingfang returns a shot to Judith Meulendijks of The Netherlands during a women's singles first round match at the All England badminton championships in Birmingham March 7, 2007. [Reuters]

"I started to coach Xie ever since 2000 when she was recruited into the national team," said Tang, adding:"She is not physically strong, and has to strengthen her muscles. However, we have done a lot but it has not proved fruitful."

Tang said that Xie, two-time winner in 2005 and 2006 world championships, was an obedient player.

"But she is a little bit introverted. So quiet. It's hard for us to communicate. That's why she cannot find her form easily on the court."

"Technically speaking, Xie relies on speed and does well in running but lacks changes on shuttlecock routes."

When commenting on Xie's mental strength, Tang said:"Not very good since she has not played China 's first women's singles in big events like Olympic Games and Uber Cup. Ever since 2007, we try to separate her and Zhang Ning in order to let her play more foreign players on her own."

Tang said that although Xie won quite a few matches but mostly by 2-1. "She actually can not control the game."

Tang suggests that Xie still require an overall improvement.

"Only if she has a big advantage over the rest, she can dominate the match and charge for the Olympic gold medal in Beijing." said Tang.