Gade, the third seed in the men’s singles, aggravated a foot injury in his first round victory over Eric Pang and was advised to take a short break on Wednesday.
The Dane, who will retire this year, is preparing for his final European Championships in three weeks’ time as well as the Olympics in July.
His back luck meant Kazumasa Sakai of Japan went through to the third round, where he will play former world junior champion Viktor Axelsen of Denmark.
On Thursday, women’s fourth seed Jiang Yanjiao joined world champion Wang Yihan (above), on the sidelines.
Wang Yihan, who was hoping to bounce back after suffering a surprise loss in the All England final to teammate Li Xuerui, struggled in the opening round against Indonesian qualifier Adrianti Firdasari, dropping the first game before winning 19-21, 21-15, 21-16.
Jiang Yanjiao (right), had an easy first round match against Swiss wildcard Jeanine Cicognini, winning 21-8, 21-14.
The withdrawal of the two Chinese stars meant that Japan’s Minatsu Mitani and South Korea’s Sung Ji Hyun have qualified for the quarter-finals.
Two other Chinese seeds, world No. 3 and second seed Wang Shixian and sixth seed Liu Xin are still in the running to win the tournament.
Wang Shixian defeated Singapore’s Fu Mingtian 21-9, 21-13, and will now face Germany’s Julian Schenk for a place in the semi-finals.
Liu Xin edged another Singaporean, Gu Juan 21-14 18-21 21-18, and will take on India’s Saina Nehwal, who also needed three games before beating Dutch qualifiers Judith Meulendijks 19-21, 21-10, 21-6.
Saina, who lost her No. 4 spot in the world rankings to Li Xuerui, has not been performing well of late and needs a good run here to help her confidence ahead of the Olympics.
For full results, click here.