Serena Williams has withdrawn from next week's Wuhan Open, as well as the China Open, with a shoulder injury.
Williams, 34, has been troubled by the problem with her right shoulder since winning Wimbledon, her 22nd Grand Slam singles title, in July.
She says her focus is now on being fit enough to play in the season-ending WTA Finals in Singapore from 23 October.
Her recent defeat to Karolina Pliskova at the US Open ended Williams' 186-week run as world number one.
She had equalled Steffi Graf's record for the longest reign at the top of the women's rankings.