Serena Williams has withdrawn from next week's China Open due to illness and Venus Williams has withdrawn due to a back injury, a source at the WTA has confirmed.
Early Thursday morning, the China Open's official account tweeted via the Chinese Twitter service Weibo that Serena had withdrawn from the tournament due to the flu and would be replaced by Romina Oprandi. Later in the afternoon, Serena tweeted her flu-like symptoms.
Serena has a history of keeping her post-U.S. Open schedule notoriously light. Since 2005 she has played Beijing only once, in 2009, which also happens to be the first year it was made mandatory and the last year she qualified for the WTA's season-ending Championships.