By Martyn Herman
RIO DE JANEIRO (Reuters) - World number one Novak Djokovic will face Argentina's Juan Martin del Potro, the player who denied him a medal in London, in the opening round of the Rio Olympics after the draw was made on Thursday.
Defending men's singles champion Andy Murray will take on Djokovic's Serbian team mate Viktor Troicki in round one while women's singles champion Serena Williams opens her campaign against Australia's Daria Gavrilova.
Women's second seed Angelique Kerber of Germany begins her medal quest against Colombian Mariana Duque-Marino.
Former Olympic champion and third seed Rafael Nadal of Spain, out with a wrist injury since the French Open, plays Federico Delbonis in round one.
Djokovic, chasing the Olympic gold medal that is the only major honour missing from his glittering CV, lost to Del Potro in the bronze medal match at the 2012 Games.
They will face off early on Saturday when the tennis competition begins on the Olympic Park hardcourts.
Women's French Open champion Garbine Muguruza will play former world number one Jelena Jankovic.
Several top names, including 17-times grand slam champion Roger Federer, fellow Swiss Stan Wawrinka and Tomas Berdych, are not competing in Rio.
The tennis competition also includes men's, women's and mixed doubles.
(Editing by Ed Osmond)