British number one Johanna Konta has pulled out of the Canadian Open with a knee injury.
The 30-year-old was due to face 15th seed Coco Gauff in the third round, with the American now advancing to the quarter-finals in a walkover result.
The event in Montreal was Konta's first since the Nottingham Open in June.
She pulled out of Wimbledon when a member of her team tested positive for Covid-19, then missed the Olympics after contracting the virus herself.
On her return to action, Konta got past Zhang Shuai in the opening round after the Chinese player retired with a leg injury when 5-2 down to the Briton in the second set, having claimed the first.
Konta then fought back from a set down to defeat third seed Elina Svitolina to set up the third-round meeting with Gauff.