American teenager Amanda Anisimova has pulled out of the US Open after her father died.
The Women's Tennis Association (WTA) confirmed the news and said it sent its "deepest condolences" to Anisimova, with fellow players also expressing sadness over the death.
Russian-born Konstantin Anisimov played a key role in coaching his 17-year-old daughter, who reached the French Open semi-finals in June.
No details of his death have been given.
Anisimova is ranked 24th by the WTA, climbing rapidly after beginning the year as the world number 95.
Fellow American teenager Coco Gauff, who Anisimova beat in the girls' singles final at the 2017 US Open, wrote on Twitter: "Deepest condolences to the Anisimova family during this tragic time"
Maria Sharapova was another to express her sorrow at the news.
Anisimova has been out of action recently because of a back injury but was hoping to play the final grand slam of the year.
The tournament begins next Monday, August 26, at Flushing Meadows in Queens, New York.