BEIJING - Li Yongbo, head coach of the Chinese national badminton team, said on Tuesday that world number one Lin Dan must improve both tactically and mentally after his disappointing performance at the Sudirman Cup competition.

China's Lin Dan gestures during his singles badminton match against South Korea's Shon Seung Mo at the semi-finals of the Sudirman Cup World Team Badminton Championships in Glasgow, Scotland June 16, 2007. [AP]

"In contrast with the previous key contests he played, Lin failed to hitch his wagon to a star," said Li upon his arrival in Beijing on Tuesday.

Despite a lackluster Lin, the all-mighty team enjoyed a plain sailing as they claimed the Sudirman Cup for the record sixth time after beating Indonesia 3-0 in the final last Sunday.

"Lin now lacks the passion on court, this was one of his best qualities he presented in the past events," Li said. "We had a discussion (after the Cup). He (Lin) thought the result was the most important thing, but the coaches are concerned about the process as well. He needs to win every match even though the result has been decided."

"At the same time, Lin's tactics are also expected to be adjusted as other top players around the world are improving so fast. Lin needs to maintain his momentum and raise his game before the 2008 Olympics."

Li, nicknamed "Super Dan" by his Chinese fans for his badminton talents, had a poor run of form at the world mixed team badminton championships, losing to Asian champion Lee Chong Wei in straight sets last Thursday when heavy favorites China had been expected to present another whitewash in their final round-robin match against Malaysia. China finally won the match by 4-1.

It was the first time since the 2003 final that China had not won a Sudirman Cup match 5-0.

Lin also played some sloppy moments in the semifinals against South Korea when he survived a mid-game scare in men's singles before finally clinching a 21-11, 18-21, 21-14 win over Olympic silver medallist Shon Seung Mo.

"We want to win the trophy but also use the tournament as warm-up for the Olympics. Everyone shares equal chance and if you don't give your best, you could be out at anytime," the coach had said during the Cup competition held in Glasgow, Scotland.