 Venus Williams, Maria Sharapova, Ana Ivanovic, Kim Clijsters and John Isner had all been in doubt after suffering minor injuries during lead-up tournaments but all were cleared to play.In a second round match played in 40-degree heat, Belarusian 10th seed Victoria Azarenka collapsed whilst trailing Gisela Dulko 1–5 in the first set.Azarenka was subsequently taken to hospital in a wheelchair where she was diagnosed with mild concussion and later released a statement saying that a mishap in the gym, and not the heat, caused her to collapse during the match.