Two-times Grand Slam champion Coco Gauff has parted ways with coach Matthew Daly just days before the start of the US Open, ESPN reported on Wednesday.
World number three Gauff will continue to work with longtime coach Jean-Christophe Faurel and has also brought biomechanics specialist Gavin MacMillan.
She was seen training on Wednesday at the Billie Jean King Tennis Centre in New York with both Faurel and MacMillan, who previously worked with world number one Aryna Sabalenka, helping her with her serve and forehand.
Gauff's own serve has been under scrutiny. She committed 42 double faults in just three matches at the Canadian Open earlier this month, part of a season-long pattern that has seen her rack up a tour-leading 320.
Under Daly and Faurel, Gauff enjoyed some of the best results of her career, including winning the WTA 1000 China Open, the WTA Finals, and this year's French Open. However, her recent form has dipped, with just four singles wins since Roland Garros and a first-round exit at Wimbledon.
The US Open main draw begins Sunday, with 2023 champion Gauff set to appear in a Thursday night exhibition at Arthur Ashe Stadium.

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