Final seedings announced Wednesday see Swiss number one Roger Federer, who is looking to win his first Olympic singles gold medal, topping the men’s bracket over number two Novak Djokovic, who won bronze in Beijing.

Defending champion Rafael Nadal had to withdraw from the competition last week due to a knee injury.

Victoria Azarenka tops the women’s seedings over Wimbledon runner-up Agnieszka Radwanska. Defending champion Serena Williams is the fourth seed.

In the women’s doubles competition, Liezel Huber and Lisa Raymond are the top seeds, while Bryan twins Mike and Bob head the men’s competition.

The singles seeds are based on the ATP and WTA rankings from July 23, while the doubles seeds are based on the combined ATP or WTA rankings of each team, with each player using the higher of their singles and doubles world rankings.

The organizing committee said that if there were two players or doubles teams from the same country, they will be drawn in opposite halves of the draw, irrespective of seedings.

If there are three or more players from the same country, they will be drawn in different quarters of the draw, which will be held on Thursday.

Entries for the 16-team mixed doubles will only be finalized on July 31.