Coco Gauff, the 2023 US Open champion, stunned the tennis world by parting ways with coach Matt Daly just days before the 2025 US Open, starting August 24, citing a need to address her faltering serve and long-term game vision. Speaking at her media day on August 22, Gauff called the decision “sudden” but necessary, stating, “Gavin [MacMillan] became available. I felt this was the best decision for my game. I’m looking long-term.” The move comes as a worrying stat highlights her serving struggles, with Gauff leading the WTA with 320 double faults in 2025, including 42 across three Canadian Open matches.
Gauff’s Reasoning and New Direction
Gauff, seeded third, explained her split with Daly, a grip specialist who helped her win the 2024 China Open, WTA Finals, and 2025 French Open, was driven by a desire to refine her serve and forehand. “I know where I want my game in the future. I’m not going to waste time playing the way I don’t want to,” she told reporters. Her new coach, Gavin MacMillan, a biomechanics expert who fixed Aryna Sabalenka’s serve in 2022, joined her practice sessions at Arthur Ashe Stadium, focusing on her ball toss and weight transfer. Gauff’s second-serve win rate of 48.5% lags behind Sabalenka’s 52%, underscoring the need for change.
The Worrying Stat
Gauff’s 320 double faults in 2025, averaging 9.2 per match, dwarf Elena Rybakina’s 4.2, with a career-high 23 in a single match against Danielle Collins at the Canadian Open. Her struggles continued with 16 double faults in a Cincinnati quarterfinal loss to Jasmine Paolini, contributing to a 4-4 record since her French Open title. These numbers prompted her to act swiftly, with MacMillan’s data-driven approach seen as key to reducing errors, as ESPN’s Darren Cahill noted: “He breaks down biomechanics thoroughly.”
Outlook and Context
Gauff’s bold move, likened to Emma Raducanu’s coaching shifts or Luke Littler’s darts pressures, reflects her determination to reclaim her 2023 US Open form. She faces Ajla Tomljanovic in the first round, with potential clashes against Naomi Osaka and Iga Swiatek later. Fans on X are optimistic, with one post stating, “Coco’s serve with MacMillan could be a game-changer” (@TennisFanUSA, August 21, 2025). Despite a Martina Navratilova-led panel favoring Sabalenka and Swiatek, Gauff’s home-crowd advantage and MacMillan’s early impact could propel her deep into the tournament, provided her serve stabilizes.
