Jessica Pegula (No. 4)
This is the most obvious case. The American took her career by storm last summer. A title at the Canadian WTA 1000, a final in Cincinnati and at the US Open - her first Grand Slam final. She was the model of consistency.
That took Pegula into the top three. She is now ranked 4th in the world, but after her first-round loss at Wimbledon, and the fact that Iga Swiatek went ahead of her, the pressure is now increased, prompting her to commit to Washington beforehand.
Current points: 6423 / Points to defend: 2950
Emma Raducanu (No. 45)
She proved at Wimbledon that she still has a bright future on the WTA Tour, giving Aryna Sabalenka a stern test in the third round. Her performances have been encouraging since the start of the year.
However, four years on from her unforgettable triumph at the US Open, she needs an outstanding performance to really revive her career. And possibly avoid dropping out of the top 50.
Current points: 1211 / Points to defend: 108
Beatriz Haddad Maia (No. 21)
The Brazilian's 2025 season has been disappointing, with a semi-final in Strasbourg as her best result, three matches won in three Grand Slam tournaments and a terrible run of nine straight defeats at the start of the year.
Now out of the top 20, she could fall further down the rankings if she fails to shine as she did in 2024, with a quarter-final to defend in New York.
Current points: 2129 / Points to defend: 658
Amanda Anisimova (No. 7)
Six years after reaching the semi-finals of the French Open at the age of 17, she once again shone brightly at Wimbledon, overcoming Aryna Sabalenka to reach the final before falling to Iga Swiatek.
Nevertheless, she is now in the top 10, but could quickly fall out of it if she doesn't back up her run to the final at the Canadian WTA 1000. Will she be able to do so? And above all, will she overcome that 6-0, 6-0 defeat in the Wimbledon final?
Current points: 4470 / Points to defend: 758
McCartney Kessler (No. 31)
It was on the American courts that she made her name last year, winning her first-ever WTA title in Cleveland (as well as another in the W100). She has since added two more, and some fine performances, but now she will discover the pressure of defending a title.
This time around, she should be playing in all the major tournaments, and if she performs well in the two pre-US Open WTA 1000s, the top 20 will be in her sights.
Current points: 1455 / Points to defend: 375
Linda Noskova (No. 23)
Eliminated from Wimbledon by the eventual finalist Anisimova, Noskova has just achieved her best career ranking. But that's not enough for the player expected to be a future star, who hasn't always excelled this season.
And since she won a WTA 500, her first title on the circuit, during the North American tour last year, now is the time to underline her reputation.
Current points: 1867 / Points to defend: 500
Diana Shnaider (No. 15)
She was one of last season's revelations. Five titles, a fantastic rise to 11th in the world, but the hardest thing isn't getting to the top, it's staying there.
The 2025 season hasn't been as successful, and she now has a few results to defend on the cement. For the time being, she hasn't dropped out of the top 20, but if the trend of her season continues, that could well be the case.
Current points: 2526 / Points to defend: 750
Liudmila Samsonova (No. 17)
She has been a fixture in the top 20 for some time now. She's a regular, as her last North American tour in 2024 proved, but she's lacking a major breakthrough, a result that could make her a top 10 player (12th is her best ranking).
With her great serve and powerful game, the hard-court swing offers her a magnificent opportunity to finally step into the limelight.
Current points: 2576 / Points to defend: 670
Karolina Muchova (No. 12)
The story of Muchova's career is a succession of injuries that have prevented her from really competing for major titles or top 5 places.
That hasn't discouraged her, though, as she reached the last four of the US Open last year, but her season remains disappointing and still marked by injury. Will she be at her best? That is the main question.
Current points: 2718 / Points to defend: 845
Emma Navarro (No. 11)
Navarro also reached the last four of the US Open in 2024, a real revelation after beating Coco Gauff, the title holder at the time. It was her real breakthrough on the WTA Tour, propelling her into the top 10.
However, she has struggled over the last few months, remaining within striking distance of the top 10. But doing as well as she did last year will be extremely difficult. This tour will undoubtedly be a test of her calibre on the highest stage.
Current points: 3420 / Points to defend: 1313