The US Open can often throw up surprise winners - and this year's Grand Slam finale could be no exception.
With the Olympics taking place just three weeks ago, players are arriving in New York with fewer minutes on a hard court than before, and with more miles in their legs.
"I don't think anyone is coming [to the US Open] in top gear," Christopher Clarey, former New York Times tennis writer, told BBC Radio 5 Live.
"For somebody who is maybe more of a second-tier favourite, this is their year and their opportunity."
Novak Djokovic is the defending champion, but it remains to be seen if the emotional impact of winning a long-awaited Olympic gold on the Paris clay will affect his chances.
Djokovic made the Olympics his priority this year, but would love to keep his record of winning at least one Slam title every year for the past seven years going.
Victory in New York would secure his 25th major - the most of any singles player, male or female - and make Djokovic the oldest man in the Open era to win a Slam.
"The men's draw is as wide open as it has been for as long as any of us can remember," British player Naomi Broady said on BBC 5 Live.
"This year, especially with the addition of the Olympics and the players being that bit more fatigued, it is going to be incredibly interesting."
Djokovic will face tough competition from world number one Jannik Sinner, who beat him in the Australian Open semi-finals in January, and French Open and Wimbledon champion Carlos Alcaraz.
Sinner is the form player, having won the Cincinatti Open in the build-up to New York.
It was announced earlier this week that the Italian had been cleared of any wrongdoing after twice testing positive for a banned substance in March.
Alcaraz also beat Djokovic in the Wimbledon final, but the Serb got his revenge with a stunning win in the gold-medal match in Paris.
Outside of the top three, last year's runner-up Daniil Medvedev will be eyeing an elusive second Slam, while French Open finalist Alexander Zverev is also a contender.
The women's draw, too, is in a state of flux.
Coco Gauff memorably won the title at Flushing Meadows last year but has struggled recently, losing in the second and third rounds of the Canadian Open and Cincinnati Open respectively.
She has also been replaced as the second seed by Aryna Sabalenka, who triumphed in Cincinnati last week and looks a strong contender to better her runner-up showing from last year.
Jessica Pegula, born in Buffalo, New York, is also a favourite - although she will have to break her quarter-final jinx, having not progressed beyond the last eight at a major in six attempts.
World number one Iga Swiatek is always a threat, while Olympic gold medallist Zheng Qinwen and Wimbledon champion Barbora Krejcikova will be in the mix.
But injuries, illness and the switch from grass to clay to hard will have affected a number of players.
"On the women's side, it is very open," former world number one and ESPN analyst Chris Evert said.
"I do think that everyone's getting a little tired and it's been a long year. I can't say who's going to win with any kind of conviction right now."
Emma Raducanu reached the fourth round at Wimbledon in her most recent Grand Slam appearance
With no Andy Murray, much of the British focus will be on Jack Draper, Katie Boulter and Emma Raducanu.
British number one Draper will be the 25th seed and his best result at a major came in New York last year, when he reached the fourth round.
His big serving and aggressive hitting should suit the Flushing Meadows courts, which tend to play quickly.
They should also suit Boulter, who has a similarly aggressive style.
Tipped by Broady as "one to watch for the tournament", the 31st seed has yet to reach the second week of a major.
Raducanu will be returning to the venue of her astonishing 2021 triumph, where she became the first player to win a Grand Slam as a qualifier.
She skipped the Olympics to avoid the quick switch from clay to hard courts, reaching the quarter-finals of the Washington Open earlier in August, but has not played since.
"With Emma this year, it's been especially delicate for her to get her schedule right after those surgeries," Broady said.
"When you're coming back from injury, often others start cropping up because you dive in at the deep end.
"The wins she has had in the weeks she's played, she has shown she's competitive. I think the muscle memory of her win there will kick in."
This will be the first Grand Slam since Murray, the 2012 champion in New York, retired from the sport.
There will also be no Rafael Nadal, who withdrew earlier in August. The Spaniard is widely expected to retire at the end of the season, having struggled with injury over the past few years.
British number two Cameron Norrie is missing with a forearm injury, while last year's Wimbledon winner Marketa Vondrousova is also absent.
Two-time champion Naomi Osaka makes her New York return for the first time since 2022, while 2020 champion Dominic Thiem has been granted a wildcard for the final major of his career.