Rafael Nadal begins his quest for an Olympic gold medal against Italian Potito Starace, while top seed Roger Federer faces a tough opener against Russia's Dmitry Tursunov after the draw for the tennis event on Thursday.
In the women's singles, top seed Ana Ivanovic of Serbia meets Ukraine's Mariya Koryttseva. Compatriot and second seed Jelena Jankovic is up against Cara Black of Zimbabwe.
Wimbledon and French Open champion Nadal of Spain, who will overtake Federer as world number one on Aug. 18, appears to have the tougher half of the 64-strong draw which also includes Serbian Novak Djokovic and in-form Briton Andy Murray.
Third seed Djokovic plays Robby Ginepri of the U.S. Wimbledon champion Venus Williams plays Timea Bacsinszky of Switzerland while sister Serena plays Olga Govortsova of Belarus.
The tournament starts on Sunday.
