Gauff has not appeared confident with her serve since beating Aryna Sabalenka on clay earlier this summer. She won three matches in the US Open tuneup earlier at the Cincinnati Open, but lost to Italy's Jasmine Paolini in the fourth round.

Gauff hired Daly, a grip specialist, to work on her serve and forehand after she fired then-coach Brad Gilbert following a disappointing fourth-round exit at the 2024 US Open on the heels of her victory at the tournament in 2023. Daly worked with Gauff as she won the French Open this summer, claiming her second career Grand Slam tournament victory.

Coco Gauff is making a big change before her start at the 2025 U.S. Open in New York. The American tennis star has parted ways with Matt Daly, one of her coaches, while bringing in biomechanics expert Gavin MacMillan, according to multiple reports.

Gauf's last assignment with coach Matt Daly was the Cincinnati Open 2025, where she went to the quarterfinals of the competition. Earlier on Saturday, Jasmine Paolini advanced to the semifinals of the ongoing Cincinnati Open women's singles competition, defeating Coco Gauff in their quarterfinal clash..