Coco Gauff marks an intriguing prospect heading into the US Open, where she simply must be considered as one of the favourites.

And yet, there are so many factors working against her.

The youngster has struggled with her serve all year, and at times failed to find consistency in her form.

She exited early from Wimbledon, put in a solid performance at the Australian Open, and then won Roland Garros against all the odds.

Coco Gauff smilesPhoto by Al Bello/Getty Images

Coco Gauff is impossible to predict.

However, Mats Wilander still gave it his best effort.

Mats Wilander makes a prediction about Coco Gauff at the 2025 US Open

Chatting to TNT Sports, just after Wilander gave his dark horse for the US Open, he moved on to another American in Gauff.

She will naturally spearhead US hopes of a hometown winner, especially given she is the only active player, Venus Williams aside, to have actually won the event previously.

However, Wilander is not so confident for the 21-year-old this time around, admitting: “Well, Coco Gauff is always an interesting situation because, obviously, having won two majors, she knows how to win, beating Aryna Sabalenka in the French Open final, when the conditions were terrible.

“Again, it shows what guts she has, but if Iga Swiatek and Aryna Sabalenka play their best tennis, I just don’t see how Coco Gauff can keep up with them.

“But then again, are they going to be able to play their best tennis against Gauff because she defends so well? It’s actually a compliment to someone like Coco Gauff, that when she plays, she often makes her opponents play worse.”

The Swede finished by issuing a warning, first to Gauff, and then to the rest of the tour: ”I think that she has to be careful in the earlier rounds, and the later she survives in the tournament, the more of a threat she becomes.”

Coco Gauff makes huge change on the eve of the US Open

For nearly a year now, people have been imploring Gauff to take some time away to really focus on fixing her serve.

After all, it has been the outstanding and at times overwhelming issue that has prevented her from winning so many more matches.

If she were to solve that problem, it genuinely feels like she could instantly become a threat for the title of every tournament she enters. At the moment, though, nobody can predict what level she will be operating at.

Gauff, clearly well aware of these deficiencies, has decided that now is the time for change.

Coco Gauff of the United States serves during the match against Xinyu Wang of China during Day 4 of the Cincinnati Open at the Lindner Family Tennis Center on August 10, 2025 in Mason, Ohio.Photo by Dylan Buell/Getty Images

And so, as inexplicable as it may seem, Gauff has split with her coach on the eve of the US Open, and opted to bring in Gavin MacMillan, the man who is famed for fixing Aryna Sabalenka’s serving woes two years ago.

A biomechanics coach, he will offer hope of a solution to this long-term issue.

However, the timing of it all has raised eyebrows.