Roberta Vinci of Italy (AP Photo/Kathy Willens)

Leonardo Mayer of Argentina (REUTERS/Ray Stubblebine)

Ekaterina Makarova of Russia (AP Photo/Charles Krupa)

Rafael Nadal of Spain (AP Photo/Charles Krupa)

Caroline Wozniacki of Denmark (REUTERS/Adam Hunger)

Andy Murray of Great Britain (AP Photo/David Goldman)

Daniela Hantuchova of Slovakia (AP Photo/Mike Groll)

Richard Gasquet of France (AP Photo/Julio Cortez)

Marcel Granollers of Spain (REUTERS/Eduardo Munoz)

Victoria Azarenka of Belarus (REUTERS/Eduardo Munoz)