Coco Gauff ended her US Open title defense in a surprising upset 6-3, 4-6, 6-3 loss to fellow American Emma Navarro in the fourth round of the tournament on Sunday. The No. 3 seed's performance didn't help matters, ending up with 19 double faults and only 14 winners.

This loss exemplified the kind of up-and-down year for Gauff, who also lost in the Paris Olympics earlier this year.

Moreover, the loss has also sparked online discourse over the WTA No. 3's ceiling and her probable need for better coaching. As the US Open Tennis official account shared the end of the match on X, formerly Twitter, commenters flocked to throw their two cents in about Gauff.

Coco Gauff's US Open upset

Emma Navarro (USA) after beating Coco Gauff (USA) on day seven of the 2024 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center
© Robert Deutsch-USA TODAY Sports

For example, one commenter said that Gauff hasn't been on her game all year long, and her US Open flameout to Emma Navarro was no surprise.

“[Coco Gauff's] game has been a mess the entire season, how that happens with 2 coaches is what I don't get,” RoseT said.

Another person also criticized Gauff's game altogether.

“Anyone who try to say that Gauff is a tennis player, is not really watching her. Other than foot speed, a usually good backhand, she has nothing else. Hits hurting shots, and stays on the baseline. So far she has been lucky in her career,” an X user named G said.

Then, another X user seemed to agree, jokingly asking, “Will Gauff win another slam? 😂”

The same user, named Phillip Templo, Jr., also added, “I mean she has no real weapons really. She peaked just enough last year and was lucky that it happened at the US Open. Much of the hype on her was beating an aging Venus Williams.”

On the other hand, one of the few comments supporting Gauff came from a user named T-Keys 2022, who even gave her some advice.

“Coco, I'm not writing you off,” they said. “I think you need a reset. My advice is to fire your Coach. I don't think he can take you any further. Roddick only got on 1 GS [Grand Slam]. Do it before the season ends and reset for 2025. I don't feel they're serving you well with scouting reports & your serve needs to improve.”

What's next?

In Coco Gauff's third-round victory over Elena Svitolina, she has struggled with consistency by digging herself early holes through 16 unforced errors with nine on the backhand. She'd also won only 45% of her first serves in the first set.

While tennis is a long game, expending too much energy in climbing out of holes can exhaust players and make them play not to lose instead of winning.

The same thing also happened during Gauff's second-round victory over Tatjana Maria, the World No. 99. In that match, the problem was her serve, and she recorded seven double faults in the first set and only got 43% of her first serves in play.