Who is in Aryna Sabalenka's player's box at US Open 2025? All about the Belarusian's support system in New York

Defending champion Aryna Sabalenka has yet to lose a set at the 2025 US Open. In what will be a rematch of last year's title round clash, Sabalenka will face home favourite Jessica Pegula in the semifinals at Flushing Meadows on Thursday, September 4.

Marketa Vondrousova's injury-induced withdrawal before the quarterfinals handed Sabalenka a walkover, enabling the Belarusian to advance to her fourth Grand Slam semifinal this season. Sabalenka, who lost the Australian Open final to Madison Keys and the French Open final to Coco Gauff earlier this year, is yet to win a Grand Slam title this season.

Even as Sabalenka aims to win her fourth career Grand Slam at the 2025 US Open, let's get acquainted with her support system cheering on from her player's box.

Who sits in Aryna Sabalenka's player's box?

Georgios Frangulis continues to support Sabalenka at the US Open - Source: Getty

Aryna Sabalenka's player's box includes her team and support staff, primarily from her home country, Belarus, alongside boyfriend Georgios Frangulis, who has been present for the player's matches at the US Open.

Sabalenka's long-time lead coach, Anton Dubrov, is one of the regular members of her player's box, as is fitness coach Jason Stacy. Her hitting partner, Andrei Vasilevski, also lends support to Sablenka from her player's box.

Data scientist Shane Liyanage, who is also the founder of Data Driven Sports Analytics, has been part of the WTA World No. 1 player's box. Georgios Frangulis, CEO of Oakberry, who accompanies Sabalenka for many of her matches on the tour, was in New York to watch the Minsk-born player cruise through her early rounds at Louis Armstrong Stadium.

When asked if her boyfriend offers game-related advice before or after matches, Sabalenka looked pleasantly amused, clarifying that while he wasn't involved in the tennis side of things, his presence at matches meant a lot.

"I'm glad he's not giving me tennis advice, but he's always there to support me and it means a lot. It's very important for me and I'm really happy to have him by my side always supporting (me) and doing his stuff outside of the tennis community and bringing the best support for me," Sabalenka said after breezing past Cristina Busca in the fourth round.

"It means a lot and that's why I'm able to bring my best tennis everytime I'm playing tennis," an emotional Sabalenka added.

Frangulis may not be involved in tennis, but the Brazilian recently acquired a stake in French Ligue 2 side Le Mans FC in collaboration with Novak Djokovic.

While Sabalenka obviously relishes Frangulis' presence in her player's box, the entrepreneur himself admitted that being in the box was one of the "most stressful situations" that he has ever experienced.

"Definitely Aryna - she's what I enjoy the most about it! The toughest part is being in the box. It's one of the most stressful situations I've ever experienced," he disclosed a part of an interaction with claytennis.com.

"I’ve always loved tennis and been around it for a long time. Through my company Oakberry we’ve sponsored tournaments, but when you have such a personal connection with someone and with the sport, it becomes something completely different. Sitting in the box during tough matches is by far the hardest part," Frangulis explained.

Who is on Aryna Sabalenka's team at the US Open?

Sabalenka's longtime coaches in her player's box - Source: Getty

Aryna Sabalenka is obviously one who believes in longevity with regard to her team. Anton Dubrov, who was once Sabalenka's hitting partner, became her regular coach back in 2020 and has overseen her steady rise all the way to the top of the WTA rankings.

Although biomechanics expert Gavin MacMillan (who is now part of Coco Gauff's team) was roped in to assist Sabalenka with her serve in 2022, Dubrov remained in the setup, helping his protege win 14 WTA singles titles.

Fitness coach Jason Stacy, who also serves as her mental performance coach, has been working with Sabalenka since 2018 and continues to be part of her team at the 2025 US Open, as does Belarusian hitting partner Andrei Vasilevski.

Aryna Sabalenka to take on Jessica Pegula in semifinals of US Open 2025

Aryna Sabalenka has the edge over Pegula ahead of the US Open QF - Source: Getty

Aryna Sabalenka will face Jessica Pegula in the semifinals of the 2025 US Open. While a close contest is in the offing, the cards are stacked in favor of Sabalenka, who goes into the contest with a 7-2 head-to-head record against Pegula. What's more, the 27-year-old has also won the last three encounters played by the duo.

After getting the better of Pegula on the hard courts of Cincinnati before last year's US Open win, Sabalenka defeated the American in Miami earlier this year. In terms of Grand Slam success, Aryna Sabalenka won the Australian Open twice (2023 and 2024) before triumphing in New York last season.