Coco Gauff fires coach Matt Daly and hires Aryna Sabalenka’s ex-biomechanics coach

Coco Gauff is making major moves just days before the start of the US Open as ESPN reports that the world No. 2 fired coach Matt Daly and brought in biomechanics coach Gavin MacMillan.

Since completing a triumphant run at the French Open, the new two-time Grand Slam champion has been subpar with her game and results as she is only 4-4 over the past three months. After disappointingly losing in the Wimbledon first round, the American tennis star started to again experience major issues on her serve and spray double faults. 

Across three matches played in Montreal, Gauff hit a stunning total of 43 double faults. In Cincinnati, the world No. 2 lowered her double-fault number in her opening two wins but then blasted 16 double faults during a round-of-16 loss to Jasmine Paolini. Overall, the 21-year-old has hit 320 double faults in 2025. 

Now, just a couple of days before the start of the US Open, Gauff decided to say goodbye to Daly, whom she hired last fall after splitting with Brad Gilbert. During their stint, the American won her maiden WTA Finals title and added another Grand Slam to her collection. 

Gauff hires the same biomechanics coach who helped Aryna Sabalenka

If you can recall, Sabalenka struggled mightily with her serve and double faults in 2022. But after hiring MacMillan, that quickly changed and she became a Grand Slam champion and the world No. 1 the following year. 

Now, Gauff will hope that MacMillan can also correct her serve.

It is worth mentioning that after exiting last year’s US Open, the American was asked if she could pull off a Sabalenka and turn to a biomechanics coach.

“Yeah. I mean, for sure. Yeah, I definitely want to get other opinions. Because, you know – and also I think it’s sometimes more of an emotional, mental thing because if I go out on the practice court right now, I would make, like, 30 serves in a row. I’ve done it before,” Gauff said at the time.