Top seed Svetlana Kuznetsova will not defend her China Open title after pulling out with an abdominal strain.
Kuznetsova beat Mauresmo to win the Beijing title last season
The world number two lost the US Open final and then led Russia to victory in the Fed Cup in the last two weekends, and the injury has caught up with her.
"It's getting worse and worse," said Kuznetsova, 22. "I came here and had treatment but I just cannot serve."
Justine Henin, who beat Kuznetsova in New York, withdrew from the Beijing event last week because of illness.
The world number one had been suffering from respiratory problems.
The China Open did provide opening victories for two other players on the comeback trail.
Lindsay Davenport, who won the Bali Classic title last weekend just three months after giving birth to her son, swept past fellow American Julie Ditty 6-0 6-2 in the first round.
And French third seed Amelie Mauresmo, who has been struggling with injury since July, beat Romania's Raluca Olaru 6-2 6-2 in their second-round match.