World number one Victoria Azarenka has been forced to pull out of the Rogers Cup in Montreal with a knee injury.
The top seed had been due to play Austria's Tamira Paszek in the second round on Friday.
However, she has now withdrawn from the tournament with the knee problem.
Azarenka becomes the second high-profile casualty at the Canadian tournament after Maria Sharapova pulled out with a stomach virus on Wednesday.