Coco Gauff has has fired one of her coaches on the eve of the U.S. Open and brought aboard the serve doctor who helped No. 1-ranked Aryna Sabalenka work on her issues with that part of the game.

Gauff said, "I'm obsessed with the process of getting better. ...I feel like I have a clear future where I see myself and I feel like I'm really close."

Tennis superstar Coco Gauff has parted ways with her coach just days before this year’s US Open, according to reports, including ESPN, on Wednesday.