Aryna Sabalenka has withdrawn from the China Open due to an injury suffered during her title-winning campaign at Flushing Meadows, organisers said on Wednesday.
The Belarusian, who defeated Amanda Anisimova to win a second straight US Open crown and fourth Grand Slam title earlier this month, reached the quarter-finals of the WTA 1000 event in Beijing last year.
"I am sad to announce my withdrawal from the China Open this year after sustaining a small injury after the US Open," Sabalenka said in a statement provided by organisers.
"I am going to focus on being 100% healthy for the rest of the year ..."
American Coco Gauff is the defending champion at the China Open, which will take place at the National Tennis Centre in Beijing from September 24-October 5.

Real Sociedad beat Atletico Madrid on penalties to win Copa del Rey
Cunha strike earns Man United hard-fought 1-0 win at Chelsea
One driver dead, six injured in Nuerburgring race crash
Brighton's Rutter denies Tottenham crucial victory with last-gasp strike
France's Pin becomes first woman to drive a Mercedes F1 car
