Tennis news - Four outside contenders for the 2019 US Open

The 15-year-old Gauff is making her return to the limelight after her breakthrough tournament at Wimbledon earlier in the summer. There she reached the fourth round of the tournament before being eliminated by Simona Halep, one of the strongest players on the women's circuit. Before then she had beaten Venus Williams - ranked 44 in the world but nevertheless a heavy favourite before the match. While Wimbledon made her known to a wider audience, she had already reached the second round of the season's French Open, suggesting that there is plenty of improvement yet to come for the teenager.

Because of WTA rules over the amount of tournament tennis she can play at her age, her development post-Wimbledon has not notably come in professional games. She did, however, lay down a marker with an exhibition match against Ash Barty at the Winston Salem Open. She beat the Australian world number two in a 6-4, 2-6, 10-8 encounter, which will have helped prepare her for a physically demanding US Open.

While few expect Gauff to win the whole tournament, the wildcard entrant will be regarded as more than just a potential upset for more established players. She is already set to be a major star in the coming years, and if her development goes according to plan, it is just a question of when.

It is rare that a 19-year-old will appear to be a veteran, but Canadian Bianca Andreescu is something of a journeywoman compared to Gauff. Andreescu has racked up a number of high profile victories already this year, downing Elina Svitolina, Angelique Kerber and Garbine Muguruza on her way to winning the Indian Wells title.

While Gauff has been prevented from taking in part in too many tournaments due to WTA regulations, Andreescu has been absent from major tournaments due to injury, with a shoulder problem causing her to withdraw from this year's French Open. Playing in the Rogers Cup as part of her return to competitive behaviour gave her the chance to reacquaint herself with victory. She defeated both Karolina Pliskova and Kiki Bertens on the way to the final. Serena Williams was her last opponent and Williams' back spasms allowed her a comfortable victory.

The Canadian has committed to recovering fully from her troublesome shoulder and will be aiming to test herself against Williams or any other challenger at the US Open.

Canada also have Felix Auger Aliassime to compete in the men's side. Like Andreescu, he is just 19 but is seen as a credible challenger to established player on the circuit and is now ranked 19th in the world. He won his first ATP match at the Indian Wells event in 2018, and he reached the Miami Masters semi-final this year, the third-youngest player in history to do so.

At the majors he is yet to break through but progressed to the third round in Wimbledon this summer. That was his best showing in a Grand Slam event so far, having made it through to just the first round in the US Open last year and not getting out of the qualifiers for either the Australian or French Open events yet.

Mats Willander is predicting a big future for Aliassime, telling Eurosport: "I think Felix Auger Aliassime... He’s most probably the one who has the best chance of doing something that’s extraordinary."

2019 marked the year that Daniil Medvedev broke into the top five of the men's world rankings, and with Roger Federer, Novak Djokovic and Rafael Nadal into their thirties, he could be in line to take the number one spot before the next wave of players come through to challenge for the Grand Slam events. Medvedev has underwhelmed in every major event so far, with his best showing being the fourth round in Australia. Last year in the US event, he reached the third round.

He had no Masters titles to his name until the Cincinnati Masters last week, in a match which may point the way to more success in the future. It was in the semi-final that he defeated Novak Djokovic before beating David Goffin in straight sets to claim victory. That win came off the back of a strong showing in the Rogers Cup in Canada, where he defeated both Dominic Thiem and Karen Khachanov before losing to Rafael Nadal in the final.

It was after his Cincinnati defeat that Goffin described just what he offers as an opponent: "He counters you really well. He's not easy to play. Side to side, he's moving okay for a big guy. And he just doesn't miss.

"So you don't know between to be solid or attacking. He's a really good player, really good player. And on that kind of surface when it's tough to control the ball, he's just solid. It's tough to make winner, to be precise. He's really good, unbelievable the level he had the last three weeks."