Just days before the 2025 US Open, Coco Gauff welcomed a new coach, Gavin MacMillan, to her team. Her primary goal was clear — to eliminate her double faults. In 2025 alone, she recorded around 306 double faults in 46 matches. That’s a worrying number, as double faults directly hand points to opponents, shift momentum, and pile pressure on Gauff. However, according to her new coach, there’s another area of her game that needs attention first.

MacMillan is the same coach who helped Aryna Sabalenka overcome her serving struggles — using biomechanics as the key to success. Now, as Gauff and MacMillan begin their partnership, many in the tennis community are wondering whether there’s more than just double faults to fix. That very question came up during MacMillan’s appearance on Tennis Channel. According to him, “The goal for her, not first and foremost, is to establish an effective kick serve.”

Once that foundation is stable, they’ll build on it with more aggressive first-serve strategies, adding both velocity and spin. The philosophy, MacMillan explained, was inspired by UFC Hall of Famer Georges St-Pierre, who once said that when you get hit, you have to go back to your roots.

MacMillan elaborated, “The first goal is obviously, in my mind, to get an effective kick serve that she 100% trusts. And once we have that in place, we can start establishing, you know, hitting more effective first serves that not only have velocity but spin. It’s not just one thing to hit it hard. If you hit it hard and it bounces flat, it’s into everybody’s wheelhouse.”

MacMillan emphasized that straight fastballs simply don’t work — speed must come with movement. These, he said, are the two immediate goals for Coco Gauff. Naturally, this approach has fueled optimism among fans, who see Gauff’s journey as a potential redemption arc. Even Serena Williams’ former coach, Rick Macci, seems to share that optimism.

Coco Gauff might ace her serves in the upcoming season

Gauff showcased remarkable form in Wuhan, where she captured the WTA 1000 title. Yet, her serve continued to hold her back. But that might soon change. Taking to X, Rick Macci expressed confidence that Gauff’s struggles were nearing an end. He noted that she now realizes the need to “rewire the forehand” and “have a science-based ATP blueprint.” According to him, she needs two pronations to produce faster, more compact serves.

And with that, Coco Gauff could become a true powerhouse. Macci added, “Her serve will become a weapon. If she unplugs this December, does reconstructive surgery, rewires the muscle memory, and learns the ATP forehand, she will be able to hold the baseline and dictate instead of defend.”

Still, Gauff remains one of the best players in the world — already armed with the skills to win big. With biomechanics refining her serve and renewed technical focus sharpening her forehand, Coco Gauff seems ready to rebuild the very foundation of her game. If these adjustments click, the double faults that once haunted her could soon transform into the weapon that fuels her next Grand Slam triumph.

But what do you think — can Gauff overcome her weakness by the 2026 season?