An eight-month doping ban has taken a toll on the mind of former badminton world number one Lee Chong Wei, Malaysia's national team coach said.
Lee, twice an Olympic silver medallist, only returned to action last month after he tested positive for dexamethasone at the world championships in August last year.
He won his first tournament since the ban last week in New York and goes for his second in Canada on Sunday against Hong Kong's Angus Ng Ka Long.
While the victories keep coming at the lower ranked events, the 32-year-old Lee has struggled with the demands of competing again as he races to get himself tournament ready ahead of the world championship in August.
"He's not physically tired, but the back-to-back individual tournaments he's competing in after an eight-month lapse is definitely taking its toll on him mentally," national coach Hendrawan told the Star.
"Chong Wei and I assessed his game after the quarter-final match. He admitted that it was tough to stay focused in every game. He is getting tired by the day."
Lee has surprisingly dropped sets in his last three rounds in Canada, but will be favourite to take the title in Calgary against an opponent he has never met before and who celebrated his 21st birthday on Wednesday.
Lee's ranking has slumped to 180th after his doping ban but a win in New York rocketed back into the top 100 and Hendrawan said the intense returning schedule, which also included the Sudirman Cup and Southeast Asian Games, would benefit the shuttler.
"It's good that his world ranking has improved from No. 180 to No. 99 - thanks to his win in the US..but it's not just about world ranking," he said.
"The matches here are also about helping him to rebuild confidence, ease back into the tournament-mode and regain his touches. All these are crucial in his preparation for the World Championships."