Coco Gauff is heading back to the Slam that defined her career. At just 19, she made history by winning the 2022 US Open, but the years since have brought both highs and lows. In 2025, she claimed the French Open title, yet the season has been rocky overall. Across 47 matches, she’s racked up a staggering 320 double faults, leading to tough exits after Paris. Now 21, Gauff has taken decisive action, hiring a biomechanics expert to address her serve. Could this change spark another breakthrough?

Legendary coach Rick Macci—who trained Serena and Venus Williams in their early years—might already have the answer! Taking to X, he shared his observation: “Just from watching limited video of Coco practicing her serve major biomechanical modifications have been made and you can see the difference as symptoms are magically disappearing. Most of all she feels it and when you feel it you deal it. @CocoGauff” Could he be right?

On Wednesday, it was announced that Coco Gauff split with coach Matt Daly and welcomed Gavin MacMillan aboard, as ESPN reported. MacMillan, a former San Jose State tennis scholar and founder of Sport Science Lab, once helped Aryna Sabalenka fix her serve. Could the same magic work for Gauff?

Sabalenka’s breakthrough last year followed her partnership with MacMillan, who refined her serve and baseline game. She praised him as “an important guy in our team” and highlighted her dedication to improvement: “You always have to look for something to improve. I think I will never stop working on my serve and improving this shot. There is some gap for improvement. That’s why we’re still working.”

That coaching boost took her to consecutive Australian Open finals in 2023 and 2024, where she won the title and hit a career-high No. 2 ranking. Now, it’s up to Coco to prove if this coaching switch will help her rise again. She showed last year how far a fresh perspective could take her by bringing Matt Daly in.

Coco Gauff’s ex-coach talks working with the American

After a shocking exit at last year’s US Open against Emma Navarro, Gauff made a bold coaching change. She replaced Brad Gilbert with Matt Daly, and the move paid off quickly. The duo found instant success at the China Open and the WTA Finals. In 2025, Daly helped Gauff capture the French Open title. Under his guidance, Coco played 17 WTA tournaments and won four, including her memorable Roland Garros triumph.

Though Coco hasn’t made a public statement, Matt Daly recently confirmed the split in an interview with tennis journalist Ben Rothenberg on Bounces. He said the decision happened “recently” but had only praise for Coco: “Only have good things to say about Coco, enjoyed working with her.” Their partnership might be over, but the respect remains.

Her final tournament with Daly was the 2025 Cincinnati Open, where she reached the quarterfinals. Despite struggles this year and some tough losses from winning positions, Gauff’s match was riddled with errors—16 double faults and 62 unforced mistakes in just over two hours. Her comeback spirit is clear, but the rough patches show the work ahead.

Now, the spotlight turns to her new coach as Coco Gauff gears up for the US Open starting August 24. She opens against Ajla Tomljanovic, and fans everywhere are eager to see if this fresh start can reignite her magic on court. What do you think? Share your thoughts below!