Washington - Former world number one Victoria Azarenka of Belarus has withdrawn from next week's WTA event in Washington because of a right shoulder injury, tournament officials said Thursday.
Azarenka, the 2012 and 2013 Australian Open champion, has not been past the last eight at a Grand Slam event since losing the 2013 US Open final.
American Coco Vandeweghe was given a wildcard into the main draw. She is coming off a Wimbledon quarter-finals loss to Russia's Maria Sharapova.
Also withdrawing were Slovakia's Daniela Hantuchova due to illness and Italy's Sara Errani with a left knee injury.
The jointly staged ATP event also lost Australian Thanasi Kokkinakis, who withdrew for non-medical reasons, organizers said.