RIO DE JANERIO, BRAZIL - AUGUST 07: Novak Djokovic of Serbia (L) congratulates Juan Del Potro of Argentina after their men's singles match at the Rio 2016 Olympic Games, in Rio de Janeiro, Brazil on August 07, 2016. (Photo by Okan Ozer/Anadolu Agency/Getty Images)
Serbia's Novak Djokovic waves to the crowd with tears in his eyes after losing his men's first round singles tennis match against Argentina's Juan Martin Del Potro at the Olympic Tennis Centre of the Rio 2016 Olympic Games in Rio de Janeiro on August 7, 2016. / AFP / Roberto SCHMIDT (Photo credit should read ROBERTO SCHMIDT/AFP via Getty Images)
RIO DE JANEIRO, BRAZIL - AUGUST 07: (L-R) Richard Kruse of Great Britain competes with Alexander Massialas of the United States during Men's Individual Foil Finals on Day 2 of the Rio 2016 Olympic Games at Carioca Arena 3 on August 7, 2016 in Rio de Janeiro, Brazil. (Photo by Alex Livesey/Getty Images)
USA's Serena Williams (R) and USA's Venus Williams react after losing a point during their women's first round doubles tennis match against Czech Republic's Lucie Safarova and Czech Republic's Barbora Strycova at the Olympic Tennis Centre of the Rio 2016 Olympic Games in Rio de Janeiro on August 7, 2016. / AFP / Martin BERNETTI (Photo credit should read MARTIN BERNETTI/AFP/Getty Images)
RIO DE JANEIRO, BRAZIL - AUGUST 07: Andy Murray and Jamie Murray of Great Britain react during their defeat against Thomaz Bellucci and Andre Sa of Brazil in the mens doubles on Day 2 of the Rio 2016 Olympic Games at the Olympic Tennis Centre on August 7, 2016 in Rio de Janeiro, Brazil. (Photo by Clive Brunskill/Getty Images)
