Juan Martin del Potro of Argentina, left, shakes hands with Novak Djokovic of Serbia after del Potro won the men's singles bronze medal match at the All England Lawn Tennis Club at Wimbledon, in London, at the 2012 Summer Olympics, Sunday, Aug. 5, 2012. (AP Photo/Mark Humphrey)
Juan Martin del Potro of Argentina, left, shakes hands with Novak Djokovic of Serbia after del Potro won the men's singles bronze medal match at the All England Lawn Tennis Club at Wimbledon, in London, at the 2012 Summer Olympics, Sunday, Aug. 5, 2012. (AP Photo/Mark Humphrey)