Clive Brunskill/Getty Images
Juan Martin Del Potro (R) of Argentina waves to fans as he walks off the court after losing 4-6, 7-6, 19-17 to Roger Federer (L) of Switzerland in the Semifinal of Men's Singles Tennis on Day 7 of the London 2012 Olympic Games at Wimbledon on August 3, 2012 in London, England.