Tennis-Azarenka ruled out of Wimbledon with knee injury

LONDON, June 23 (Reuters) - Former world number one Victoria Azarenka has withdrawn from Wimbledon with a knee injury, organisers said on Thursday. Belarussian Azarenka , who would have been seeded six at the championships, has not played since retiring from a first-round match at the French Open last month. It is yet another blow for the two-times Australian Open champion who has been plagued by foot injuries. Her withdrawal means five-times champion Venus Williams will move up into the top eight seeds. (Reporting by Martyn Herman; Editing by Toby Davis)