Tournament organisers say French Open champion Li Na and Vera Zvonareva have pulled out of the Dubai Tennis Championships which start on Monday because of injuries. Organisers did not give details of the players' injuries. Last week, Zvonareva retired from the Qatar Open while trailing Monica Niculescu of Romania 7-5, 3-2 because of pain in her left hip. Australian Open champion Victoria Azarenka is the top-seeded player at Dubai tournament. The field includes defending champion Caroline Wozniacki, Wimbledon Open champion Petra Kvitova and US Open winner Sam Stosur. (For more sports news and updates, follow Ahram Online Sports on Twitter: @AO_Sports)