Serena Williams of the United States returns a shot to Urszula Radwanska at the All England Lawn Tennis Club at Wimbledon, in London, at the 2012 Summer Olympics, Monday, July 30, 2012. (AP Photo/Mark Humphrey)

Photo by: Mark Humphrey

Serena Williams of the United States returns a shot to Urszula Radwanska at the All England Lawn Tennis Club at Wimbledon, in London, at the 2012 Summer Olympics, Monday, July 30, 2012. (AP Photo/Mark Humphrey)