China will face strong challenges from Denmark, Indonesia and defending champions South Korea in their run for the Sudirman Cup, said Chinese head coach Li Yongbo Monday.

Li, showing cautious confidence in keeping the mixed team badminton championship in China, singled out the three teams one day before the six-day tournament kicks off here.

"China has been rated the strongest contender for the Cup but it is only in theory," said Li, leading the team to the women's singles, doubles and mixed doubles victories at Athens Olympic Games last year.

"Things tend to change once you are competing on the court," he added.

"I have to say Denmark, Indonesia and South Korea are all tough opponents, who have some very good playrs. We have to do our very best to beat them in order to win the trophy," he said.

Denmark, boasting men's world number two singles player Kenneth Jonassen and Peter Gade, ranked third as well as top men's doubles Jens Eriksen and Hansen Lundgaard Hansen, was pooled with South Korea in Group 1A while China and Indonesia are in Group 1B.

Kim Dong Moon and Ha Tae Kwon clinched the men's doubles title for South Korea in Athens and Indonesia takes pride in their Olympic men's singles champion Hidayat Taufik and recently crowned Swiss Open men's doubles champins Wijaya Canfra and Budiarto Sigit.

"We have been preparing for the Sudirman Cup since winter and all the players are doing well till now," said Li.