The mental toil of professional sport was made clear in a candid admission by Katie Boulter, who revealed after her US Open first-round defeat that she had to put her racket away for a week during the build-up after becoming overwhelmed by the demands of tennis.

Boulter will drop outside the world’s top 50 for the first time since January 2024 after her struggle for form continued with a 6-4, 6-4 defeat by Marta Kostyuk, the No 27 seed from Ukraine. She has won only one of six matches since Wimbledon and has experienced a poor year at the grand-slam tournaments with three second-round exits and a first-round defeat. Remarkably, for a player with great ball-striking ability, she has never gone beyond the third round at any of the sport’s four majors at the age of 29.

Facing Kostyuk first up was a tough draw and Boulter never looked as though she had a chance of coming out on top, although she battled hard towards the end of the second set by saving five match points. Afterwards she opened up about why she stepped away from tennis after the recent Canadian Open.

“Sometimes a sport can be really difficult to be in,” Boulter said. “My whole life is tennis in many different departments, so I can kind of get wrapped up into it a little bit too much. After Wimbledon I was super-motivated and probably almost worked too hard. I wanted it too much and spent more hours on the court than I ever have in my life. That then started to wear me down mentally, so I took time away from the court and talked to my psychologist.”

Although Boulter has fallen at the first hurdle in New York, it appears as if she is in a better state of mind compared with recent weeks.

“Mentally I’m now actually in a really good place and my game is improving,” Boulter said. “I do feel like the momentum is starting to roll again. It was a full reset button in the middle of the US hard-court swing. I feel like I’ve got this buzz back again, which I kind of lost a couple of weeks ago in Montreal, which was personally a really pivotal moment in my career.”

In advance of Great Britain’s participation in next month’s Billie Jean King Cup finals, Boulter will focus on fixing some critical issues with her serve. Against Kostyuk she served eight double faults and no aces, in keeping with a recent pattern of woe in this department.

Sonay Kartal of Great Britain looking frustrated during a tennis match at the US Open.

Kartal was playing in the main draw of the US Open for the first time

JAVIER GARCIA/SHUTTERSTOCK

“I need to address the serving,” Boulter said. “We’ve been trying so many different things, but nothing is quite working yet. If I can sort that, everything else will fall back into place.

“Sometimes I can lose the rhythm on the serve. And then I don’t fully commit to the serve that I’m trying to go for. I tend to get caught in between committing to the serve and then just trying to put it [into play]. But at this level just putting the serve in the court is not going to get it done.”

Asked if she would be open to following the lead of Coco Gauff and Aryna Sabalenka by hiring a specific biomechanics coach for her serve, Boulter said: “I’m completely open to ideas and I think my team are. My team is so great in this department because there are no egos. They just want me to get better as a tennis player. I saw Coco brought someone else in and I’d be tempted to do the same if it works.”

Sonay Kartal followed Boulter in making an early exit after a bizarre contest that featured both players struggling to run because of cramp towards the end. Beatriz Haddad Maia, the No 18 seed from Brazil, was 4-0 up in the deciding set when her left hamstring suddenly seized up, which followed a 20-minute period in which Kartal had been suffering cramps all over her body, including her fingers.

Haddad Maia was then given a time violation for exceeding the 25-second time limit in between points, but dug in at 4-1 up to somehow come through a Kartal service game lasting more than ten minutes before sealing a 6-3, 1-6, 6-1 victory.

It was a frustrating end for Kartal, whose physicality was a strength in helping her reach the last 16 of Wimbledon for the first time this summer.

“It was tough,” Kartal said. “I’ve never lost a match from cramp before, ever, so it was a little bit odd for me.

“When everything is locking out and you’re having to peel your thumb off the racket just to try and let go of the racket, it’s tough.You feel pretty helpless on the court.

“I fuelled up pretty well the last few days and hydrated, but it’s something that you have to get a bit picky with. We’ll look back over and analyse everything I ate and drank, and see if we can make some changes.”

Overall, this was a disappointing day collectively for the British contingent. Qualifier Francesca Jones bowed out in her first match of the main draw with a 6-0, 7-5 defeat by Germany’s Eva Lys, while Billy Harris failed to take advantage of his lucky-loser slot by losing 6-4, 7-6 (10-8), 6-4 to Felix Auger-Aliassime, the No 25 seed from Canada.