When the US Open begins next week, familiar, proven names will headline the daily schedules. But there's a good chance an outsider is going to safely navigate the crucible of the draw and grab instant attention.
And to add to the intrigue, there are a host of up-and-coming competitors ready to break out. Will one shine in the New York spotlight? Here are our top five 20-and-under players to watch:
There's no avoiding the promise of this 19-year-old from Hamburg, Germany, and that's not just because he is 6-foot-6 with a booming game. Zverev can play on all surfaces: He reached his first ATP final at a clay-court tournament in Nice and later defeated Roger Federer en route to the final of a grass-court event in Halle. After making the third round of the past two majors -- he was stopped by Dominic Thiem at Roland Garros and Tomas Berdych at Wimbledon -- you suspect it won't be long before Zverev makes more of an impression at the Grand Slams. After all, here's someone described by Rafael Nadal as "a clear possible future world No. 1, who is amazingly talented and has all the shots." Zverev has yet to win a main-draw match at the US Open.
2. Daria Kasatkina
Will the 19-year-old Russian make the second week of a Grand Slam for the first time? She has reached the third round of this season's first three majors, as well as the last 32 at the 2015 US Open, so it's surely only a matter of time before she goes deeper into the draw. Kasatskina couldn't have come any closer to cracking the final 16 at Wimbledon. Venus Williams needed all her guile and power to fend off Kasatskina in their third-round match, with the former champion eventually taking the decisive third set 10-8. Still, it's not as if Kasatkina missed out on beating Williams for the first time, as she had already done so in Auckland at the start of the season.
3. Taylor Fritz
No one has ever accused the Californian -- the youngest man inside the top 100 -- of meandering his way through life. At the age of 18, when his friends are preparing to go to college, Fritz is already married (he proposed during this year's French Open and the wedding took place just after Wimbledon) and has established himself as a top-level player. Already this season, Fritz played in his first ATP final following a run on the hard courts of Memphis, where he was stopped by Kei Nishikori. And there's something this ambitious young man will want to accomplish early on at the US Open: winning a match in the main draw of a Grand Slam for the first time.
A quarterfinalist at Flushing Meadows in 2014, Bencic is still only 19 years old. As she once mused when trying to explain why Switzerland keeps producing such classy players: "There must be something in the chocolate." And yet, after a summer of injuries, it's difficult to be sure how she might perform on the cement of New York. After missing the French Open because of a bad back, she retired from a second-round match at Wimbledon after hurting her wrist. She also lost so many training days while healing that she decided it would be best to give the Olympics a pass and instead focus all her efforts on New York.
At 5-foot-7, the 20-year-old Japanese player is almost a foot shorter than Juan Martin del Potro. He's also three inches smaller than countryman Nishikori, the 2014 US Open finalist, who at 5-10 himself is considered to be on the short side for a professional tennis player. Still, that lack of stature hasn't stopped Nishioka from breaking into the top 100 or reaching his first ATP semifinal in Atlanta. This summer's hard-court swing has seen a new, more stable version of Nishioka. While he was once, in his own words, "very emotional, throwing rackets and getting frustrated," he has been much calmer on the court over the past few weeks. This will mark the third consecutive summer he has played at the US Open, but this is the first time he has gained direct acceptance after qualifying in 2014 and 2015.