Coco Gauff has continued to struggle on her serve despite working with a biomechanics coach for the best part of six months.
Gauff, the American number one, hired biomechanics specialist Gavin MacMillan last August in the hope of fixing her troublesome serve.
MacMillan is widely regarded as an expert in his field and previously helped Aryna Sabalenka to correct her serve.
Where will Coco Gauff be ranked at the end of 2026?
However, MacMillan’s influence on Gauff’s serve appears to have been limited so far, as the 21-year-old continues to hit double faults at an alarming rate.
Rick Macci, the former coach of the Williams sisters, has weighed in on Gauff’s serve and suggested how the American can improve the shot.
Rick Macci says Coco Gauff should change to a platform stance on her serve
Rick Macci, the former coach of Serena and Venus Williams, is an authority on all things tennis and an individual who continues to offer his thoughts on the current affairs of the ATP and WTA Tours.
The American coach, who has also worked with Andy Roddick and Maria Sharapova, believes progress has been made on Coco Gauff’s serve, despite her recent double-fault troubles.
In a post on X [formerly Twitter], Macci said: “Coco and her serve is biomechanically better.
“Gavin identified the real problems and I see it is stabilized. But because she is double-jointed and her wires are so free flowing she has more shake and bake that causes extra movements in the arm without trying.
“I would go to a tight platform stance and put her on lockdown from the ground. Be in a cylinder bubble and no more double.”
Gauff’s serve preparation would change significantly if she heeds Macci’s advice.
The American currently hits her serve using a pinpoint stance: bringing the back foot up to meet the front foot during the loading phase.
If Gauff were to switch to a platform stance, she would keep her feet apart throughout the service motion.
| Tournament | Opponent | Double Faults |
| 2026 Australian Open | Kamilla Rakhimova | 7 |
| Olga Danilovic | 4 | |
| Hailey Baptiste | 6 | |
| Karolina Muchova | 3 | |
| Elina Svitolina | 5 | |
| 2026 Qatar Open | Elisabetta Cocciaretto | 3 |
| 2026 Dubai Tennis Championships | Anna Kalinskaya | 12 |
| Elise Mertens | 16 | |
| Alexandra Eala | 8 | |
| Elina Svitolina | 12 |
What did Coco Gauff say about her serve after hiring Gavin MacMillan?
After defeating Alja Tomljanovic in the US Open first round, Gauff discussed how she would look to alter her serve.
“I think it’s all mechanics,” Gauff said, as per Olympics.com. “Now it actually makes sense, and now it’s just really trusting that new motion in those moments.
“When I do it, it’s always a good result – it’s just reminding myself how to do it. I’m trying not to become as obsessed with it, but it is a bit because this is the part of my game that needs to improve if I want to get the results that I want.”
Where will Coco Gauff be ranked at the end of 2026?
“It’s a new motion, at times I can do it well, at times not so well. When I do it, it’s always a good result – it’s just reminding myself how to do it.”
Gauff will find out her next opponent on Monday when the Indian Wells draw is released.
Gauff has never won Indian Wells: she achieved her best result in 2024, reaching the semi-finals before losing to Maria Sakkari.
Last year, Gauff reached the fourth round before losing to Belinda Bencic.
