Victoria Azarenka pulls out of the tournament in Toronto . Two - time Australian Open winner has a back injury . She lost in the quarterfinals of the tournament to Samantha Stosur . Australian Open champion Victoria Azarenka has joined the growing list of injury casualties at the WTA Rogers Cup tournament in Toronto . The tournament starts Monday with Novak Djokovic cefending title .
Victoria Azarenka pulls out of the tournament in Toronto . Two - time Australian Open winner has a back injury . She lost in the quarterfinals of the tournament to Samantha Stosur . The tournament starts Monday with Novak Djokovic cefending title .