Bertens thought the risks were too great, because of the coronavirus situation in the United States. She was preparing for Roland Garros, her favourite grandslam tournament, which starts in a weeks time.
The Japanese Naomi Osaka, who won the US Open, rose from ninth to third place. The Australian Ashleigh Barty leads the list, in front of the Romanian Simona Halep.
With the men, the final was only over late Sunday evening. The Austrian Dominic Thiem won from the German Alexander Zverev. The top nine is still unchanged. Spaniard Pablo Carreno Busta, who reached the semi-finals in New York, has climbed from 27th to 18th position.
Greek track best among men
Tallon Griekspoor is the best Dutchman in 138th place, followed by Botic van de Zandschulp (164th) and Robin Haase (171st).