US Open: Emma Raducanu, Vicky Mboko, Joao Fonseca – who are tennis’ brightest young stars to watch out for?

Who are tennis’ great disruptors? The game’s best and brightest young stars capable of causing an upset at the US Open?

Come the conclusion of the next fortnight at Flushing Meadows, it would be no great shock to see world No 1s Jannik Sinner and Aryna Sabalenka retain their singles titles and for tennis to stay with the status quo.

In the men’s game, since Stan Wawrinka’s 2016 US Open triumph, Dominic Thiem (2020) and Daniil Medvedev (2021) – both doing so in New York – are the only players not named Roger Federer, Rafael Nadal, Novak Djokovic, Carlos Alcaraz or Sinner to win any of the past 34 Grand Slam tournaments.

As for the women’s game, while it has been a touch more open, the world’s top three of Sabalenka, Coco Gauff and Iga Swiatek have combined to take 10 of the last 14 Slams.

But if there is to be an upset at the US Open, who are the players most capable of delivering it? Here, we pick out tennis’ best young hopefuls dreaming of making a dent in this latest era of dominance…

Mirra Andreeva

Still just 18 years old, and already boasting two Grand Slam quarter-final runs in 2025 alone – at the French Open and Wimbledon – as well as a final-four appearance at Roland-Garros last year.

With that performance in Paris, at 17, Andreeva became the youngest Grand Slam semi-finalist since Martina Hingis in 1997, only for her teenage dreams to be shattered with a straight-sets defeat to Jasmine Paolini.

But, long touted as the next dominant force in women’s tennis, it is surely just a case of if, and not when, Andreeva fulfils her undoubted potential – and there have been plenty of positive signs in 2025.

She became the youngest-ever WTA 1000 winner with her maiden victory in Dubai in February – beating another much-heralded young talent Clara Tauson in the final – and then swiftly followed up that success with an even more impressive triumph at Indian Wells, battling back from a set down to beat world No 1 Sabalenka to the crown.

These were particularly notable victories, not only due to the high regard in which both WTA 1000 tournaments are held, nor the calibre of opponents she beat – Grand Slam champions Swiatek and Elena Rybakina also dispatched in both tournaments – but due to them coming on hard courts, particularly with an eye towards the US Open.

Flushing Meadows has thus far proven the toughest of the Slams for the teenage star to crack, knocked out in the second round in both her prior visits, while she has yet to make it past the fourth round at the Australian Open.

Could this be the year that changes?

Vicky Mboko

“I think she will be the talk of the US Open, for sure,” said Sky Sports Tennis pundit Annabel Croft after the 18-year-old Canadian’s stunning triumph at her home event in Montreal earlier in August.

Having started the year outside the world’s top 300, the teenage sensation now sits 24th in the rankings after toppling Grand Slam champions Sophia Kenin, Gauff – the top seed – Rybakina and then Naomi Osaka, in the final, to secure the coveted WTA 1000 title.

Coached by former world No 3 and 1998 Wimbledon finalist Nathalie Tauziat, Mboko claimed her first Tour victory only in March of this year, at the Miami Open, with her progress gathering considerable pace since.

She qualified for her first Grand Slam main draw at the French Open soon after, where she reached the third round, while she also pulled off an upset against 25th seed Magdalena Frech in the first round at Wimbledon.

Mboko’s magnificent victory in Montreal capped a particularly successful month for Canadian women’s tennis, with 22-year-old Leylah Fernandez, a former US Open runner-up, also winning the Washington Open in July to have her game in good order going into the final Slam of the year.

Emma Raducanu

Fernandez will be a familiar name to all you Raducanu fans, as it was her who the British No 1 famously beat to secure the 2021 US Open title at the tender age of 18.

With that incredible run four years ago, Raducanu became Britain’s first female Grand Slam champion since Virginia Wade in 1977 and the first qualifier, male or female, to win a Slam – incredibly, the teenager lifted the trophy without dropping a set over the course of her 10 matches to the title.

But, instead of launching Raducanu into a sustained run at the summit of the sport, the past four years have been beset by injury problems, coaching changes and, most recently, a stalking ordeal that left her in tears on court in Dubai earlier this year.

Despite such obstacles to overcome, there have been encouraging signs that Raducanu is getting back to her best level in 2025, just in time for her return to Flushing Meadows.

An informal coaching arrangement with Mark Petchey helped inspire a WTA 1000 career-best quarter-final run at the Miami Open, which included victories over seeds Emma Navarro (8th) and Amanda Anisimova (17th) before she was only just edged out by world No 4 Jessica Pegula in the last eight.

Raducanu also reached the semi-finals in Washington last month, beating former world No 1 Osaka along the way before losing out to Anna Kalinskaya, while Rafael Nadal’s former coach Francis Roig has since been brought in and their partnership has started in encouraging fashion as they target further Flushing Meadows success.

Joao Fonseca

This 18-year-old Brazilian wonderkid has been on many people’s radar ever since disposing of ninth seed Andrey Rublev in straight sets in his Grand Slam main-draw debut at the Australian Open earlier this year.

In doing so, Fonseca was the first teenager to defeat a top-10 opponent on their major debut since Mario Ancic shocked Federer at Wimbledon in 2002.

Fonseca followed that up by becoming the first player born in 2006 to win an ATP Tour singles title when clinching the Argentina Open in February. Beating Francisco Cerundolo 6-4 7-6 (7-1) in the final made him the 10th youngest ATP singles champion of all time, and fourth-youngest since 2000, after Japan’s Kei Nishikori and Spanish duo Nadal and Alcaraz.

Having risen to a career-high ranking of 44th in the world, further eye-catching moments this year included third-round runs at the Miami Open, as well at the French Open and Wimbledon, his time at Roland-Garros including another impressive dispatching of a seed in straight sets – Hubert Hurkacz – in the opening round.

British No 1 Jack Draper ended Fonseca’s dreams in Miami and Paris, beating him in straight sets on both occasions, but not before the Brazilian became the youngest man to reach an ATP Masters 1000 third round, and the youngest top-100 player, since a certain 18-year-old Alcaraz in 2021.

Jack Draper

Sticking with Draper, it is easy to forget the British hopeful is still only 23 years old – seeing him just about sneak into our collection of the sport’s brightest, young challengers.

Talked up for a while as a future contender, injuries severely hampered his development before his body has finally begun to play ball over the last couple of years, his immense talent taking him to a maiden ATP tour title in Stuttgart last summer, swiftly followed by another success in Vienna.

Draper had yet to make a real dent at any of the Grand Slams though, a trip to the fourth round in 2023 at the US Open his best showing in nine attempts at the majors, before he decimated that career-best with a memorable run to the final four at Flushing Meadows last year, where eventual winner Sinner proved a hurdle too far – beaten in straight sets.

Draper has since proven it was no fluke, climbing as high as fourth in the world rankings earlier this year, off the back of a stunning maiden ATP Masters 1000 win at Indian Wells – beating Alcaraz along the way, in the semis – and a run to the Madrid Open final little more than a month later.

Wimbledon was a major disappointment, losing in the second round to 36-year-old veteran Marin Cilic, with Draper saying afterwards: “It highlighted to me this year that I really struggle on the grass. I felt great on the hard court, felt great on the clay.”

Back on the hard courts of Flushing Meadows, and with such fond memories from last year, New York could prove more welcoming than his home Slam did.