Cincinnati, UNITED STATES
Juan Martin Del Potro of Argentina hits a return ball to Nikolay Davydenko of Russia at the Men's Cincinnati...
Juan Martin Del Potro of Argentina hits a return ball to Nikolay Davydenko of Russia at the Men's Cincinnati Open tennis tournament in Cincinnati, Ohio August 14, 2013. REUTERS/John Sommers II (UNITED STATES - Tags: SPORT TENNIS)