KUNSHAN • China's national badminton coach Li Yongbo declared his players were still among the best in the world but urged fans to be patient and expect occasional defeats after the hosts' shock exit from the Thomas Cup.

Under his leadership, China have dominated badminton for the past decade but unease is mounting that the team's golden era may be coming to an end.

On Thursday, China's men were knocked out of the quarter-finals of the world badminton team championship after South Korea defeated them 3-1 - the first time they have failed to reach the Thomas Cup semi-finals since their debut in 1982.

Following the defeat, fans booed and hissed as the team exited the court in Kunshan, a city near Shanghai, with some in the audience chanting: "Li Yongbo quit!"

Li said that despite the upset, the men's team were still among the best globally and called on fans to be more "understanding".

"Of course China's men's badminton team is always one of the best in the world," he said late on Saturday.

"We have to be eager for victory all the time, but we have to accept failure. If we win too much, sometimes questions will come. 'Is it positive for promoting badminton in the world?' But if we lose, sometimes questions will also come, that is the fact."

The coach said his players faced expectations similar to the Brazilian men's national football team and the United States' basketball squad - where winning is taken as the norm and defeats are rare.

The head coach also stridently defended his choice to field top-ranked Chen Long as the No. 1 singles player in the team competition over other Chinese talent, such as the legendary Lin Dan, despite Chen's recent inconsistent run.

Chen has yet to lead China to a major men's team competition. At the 2014 Thomas Cup, Kenichi Tago defeated Chen as Japan sent China packing in the semi-final.

At the Asian Games later that year, Son Wan Ho beat Chen to help South Korea claim the gold.

Son stunned Chen again on Thursday, with the world champion admitting he suffered an attack of the nerves in his 12-21, 21-16, 15-21 loss. Chen added that he was grappling with intense pressure as the world's No. 1, a position which means every opponent is determined to knock him off his perch.

"He's humble with everyone, nice to everyone but sometimes his personality may lack some power so that influences him sometimes on the court," said Li. "As long as Chen Long is happy and as long as he enjoys badminton, I still support him and will always support him."

But concerns are mounting that this week's performance may not augur well for China as they prepare for August's Rio Olympics.

Li confirmed on Saturday that Chen and Lin would represent China in the men's singles, but cautioned that competition was fierce among badminton's elite.

"If they are not careful enough, they can lose in the Olympics," said the coach.

AGENCE FRANCE-PRESSE