Main article: Tennis at the Summer Olympics — Qualification The majority of players in the singles competitions 56 of 64 players in the draw gained entry through their position in either the ATP men or WTA women rankings.
The remaining eight places were given to six players who gained ITF places wild cards and two who received invitations from the Tripartite Commission, which were intended to go to National Olympic Committees NOCs with small teams.
ITF places, ostensibly a form of wild card ,  were awarded to six players in both the men and women's singles, with one further place dispensed in the women's competition after Stephanie Vogt , entering via the Tripartite Commission, withdrew.
Sun Peng was originally the only Chinese man to enter the men's singles, and did so through the ITF places.
Open , that the Grand Slams remained the pre-eminent tennis tournaments,   the Games saw the strongest field of competition since tennis's re-introduction to the Olympics in The singles competitions featured 17 of the top 20 men, and 18 of the top 20 women, with all of the top five men in attendance.
In the calendar year preceding the Olympics, there was a shift at the hierarchy of men's tennis as Rafael Nadal displaced Roger Federer as the world number one, after his record consecutive week stay at the top of the rankings.
From the second round of the Hamburg Masters to the semi-finals of the Cincinnati Masters the last tournament before the Games , winning the French Open and Wimbledon in between, Nadal had won 32 consecutive matches. He would also be elected as Team Spain's flagbearer for the opening ceremony in Rio de Janeiro in after being forced to withdraw from the London tournament at Wimbledon due to tendinitis.
Dementieva had reached two Grand Slam singles finals and lost before her triumph here. Justine Henin , the incumbent world number one and reigning Olympic champion, retired on May 14, citing a lack of motivation for the game.
The pair were subsequently forced to withdraw from the Olympics. They were Li Na , who was a semi-finalist at the Tier I Doha before succumbing to injury for most of the Summer;  Zheng Jie , who raised hopes by becoming the first Chinese player to reach the semi-finals of a Grand Slam singles tournament at Wimbledon;  and Peng Shuai.