With the build-up to this year's U.S. Open blighted by the high-profile withdrawals of former winners Roger Federer and Rafa Nadal, as well as last year's champion Dominic Thiem, the 2021 edition could be the most open in the men's draw in recent years.
World number one Novak Djokovic, who is gunning for a calendar slam, will start as the overwhelming favourite, with Alexander Zverev, Stefanos Tsitsipas and Daniil Medvedev also in the mix.
They will, however, be wary of a string of emerging young players more than capable of causing a few upsets.
Zverev easily swept aside Andrey Rublev in the final in Cincinnati on Sunday but the highlight of the week was Rublev getting the better of Medvedev in the semi-finals, his first career win over his Russian compatriot in five meetings.
The 23-year-old fought back from a set down against the more seasoned Medvedev, underlining the potential of a player who looks set to better his quarter-final showing last year.
Rublev's recent success can perhaps be matched only by Matteo Berrettini, the big-serving Italian who has enjoyed a breakthrough season on tour.
The world number eight, who made a surprise run to the Wimbledon final last month, possesses a game that is ideally suited to hard courts, with his powerful serve and forehand bound to pose problems for opponents.
Berrettini made only the third round in Cincinnati -- his first outing since Wimbledon due to a thigh injury -- but will draw inspiration from his past performances at Flushing Meadows, where he reached the semi-finals in 2019.
American hopes will be resting on Reilly Opelka, the 22nd seed who reached his first ATP Masters 1000 final this month in Toronto, losing to Medvedev but showing enough promise to be considered a threat to some of the top-ranked players at his home Grand Slam.
The former junior Wimbledon champion has not had the most consistent year but can cause considerable damage when in form, relying on an aggressive style that is built around a huge serve.
There are others, such as Canadian duo Denis Shapovalov and Felix Auger Aliassime, who will see the absence of some of the big stars as an opportunity to make a impact at the year's final major.
Shapovalov is no stranger to the big stage. The 22-year-old went down to Djokovic in the semi-finals at Wimbledon in a match where he was arguably the better player but was undone by failing to take his chances on crucial points.
Auger Aliassime, who reached his maiden Grand Slam quarter-final at Wimbledon, was beaten by Tsitsipas in the round of 16 in Cincinnati but will be keen to build on his experience at the All England Club.
"I have had a good run in Grand Slams this year and I'm feeling confident I can go deep in New York," the 21-year-old said last week.
Among other youngsters, Jannik Sinner, winner of the Washington Open this month, and Casper Ruud, quarter-finalist at both Toronto and Cincinnati, should be exciting to watch.
While the 2021 U.S. Open might not deliver a new Grand Slam champion, it may well offer a glimpse into the future of men's tennis as the dominance of Federer, Nadal and Djokovic slowly comes to an end.