The final grand slam of the year, the US Open at Flushing Meadows, will be devoid of some of the finest talents in the men's game – and other star names may be added to the growing list.
With another top-10 player, Kei Nishikori, having pulled out on Wednesday, we take a look at the remarkable list of those who will miss out and those in danger of joining them...
OUT - NOVAK DJOKOVIC (Rank: 5; Best US Open performance: Winner - 2011, 2015)
It has not been a good year for Djokovic, whose air of invincibility has well and truly evaporated.
The 12-time grand slam champion decided last month that he would no longer battle on with a persistent elbow problem.
It forced him to withdraw from his Wimbledon quarter-final match against Tomas Berdych.
OUT - STAN WAWRINKA (Rank: 4; Best US Open performance: Winner - 2016)
Knee surgery put paid to Wawrinka's hopes of defending his US Open crown.
The Swiss had been enjoying a strong year in the slams, progressing to the Australian Open semi-finals and losing in the final of the French to a resurgent Rafael Nadal.
As with Djokovic, fitness woes hit at the All England Club, where he required ice on his knee in a first-round loss to Daniil Medvedev.
Not the place I wanted to be but 2nd surgery went well! That's mean I can start my preparation... 2018 see you soon! Thanks to all- pic.twitter.com/wGgrZpiwa6— Stanislas Wawrinka (@stanwawrinka) August 15, 2017
OUT - KEI NISHIKORI (Rank: 9; Best US Open performance: Finalist - 2014)
The Japanese called time on his 2017 season after tearing a tendon in his right wrist.
Nishikori reached the semi-finals at Flushing Meadows last year, but will not be back there this time around after suffering the injury during practice in Cincinnati.
It brings a premature end to a campaign that yielded no titles for the 27-year-old, who made it to the last eight at the French Open.
DOUBT - ANDY MURRAY (Rank 1; Best US Open performance: Winner - 2012)
Murray will soon be replaced by Nadal as world number one, the 30-year-old Brit having struggled for form and fitness.
A hip issue has blighted his season and Murray is far from certain to compete in 2017's final slam, having withdrawn from the Western & Southern Open.
The US Open was the scene of Murray's maiden major triumph five years ago.
DOUBT - ROGER FEDERER (Rank 3; Best US Open performance: Winner - 2004, 2005, 2006, 2007, 2008)
It is not part of the script in Federer's stunning renaissance story that he should now be failed by his 36-year-old body.
But the Swiss maestro was another withdrawal in Cincinnati, having tweaked his back at the Rogers Cup.
He lost in the final of that tournament, his only defeat in a title match this season, during which he has won the Australian Open and Wimbledon.
Thanks so much for all the birthday wishes from around the world! Feeling the #36 #2ndTime18— Roger Federer (@rogerfederer) August 9, 2017
DOUBT - MILOS RAONIC (Rank 10; Best US Open performance: Fourth round - 2012, 2013, 2014)
The Rogers Cup claimed another victim in the shape of home hope Raonic.
He suffered a wrist injury in a straight-sets loss to Adrian Mannarino.
Of all the confirmed and possible absentees, Raonic's record at the US Open is the least remarkable.
DOUBT - MARIN CILIC (Rank 6, Best US Open performance: Winner - 2014)
Cincinnati tournament organisers might be forgiven for taking it personally, as reigning champion Cilic was another to give that one a miss.
He won his maiden ATP Masters 1000 title there, but an adductor injury sustained during his Wimbledon final loss to Federer remains problematic.
Cilic's only slam victory came at the US Open in 2014.
|Youngs agrees new Leicester deal|
|Wozniacki slams ´rude´ umpire after Bertens win|
|Van Persie secures return to Feyenoord|
|Conte should replace Wenger at Arsenal, claims Carragher|
|Kimmich named Germany’s 2017 Player of the Year|
|Nadal´s best required against in-form Schwartzman|
|Moyes denies scouting Batshuayi and deals Chelsea blow with Carroll injury|
|Vunipola´s Six Nations hopes dashed as 12-week absence confirmed|
|No one like Ronaldinho until Messi - Guardiola lavishes praise on Brazil great|
|Simeone shrugs off mentality concerns at Atletico Madrid|
|Going for gold? Neymar meets Beckham in matching jackets|
|You think I change my mind that quick? – Klopp faithful to No.1 Karius|
|Conte backs Morata to overcome disciplinary concerns|
|Lloris a doubt for Southampton game, confirms Pochettino|
|Pieters edges into Abu Dhabi lead|
|Klopp doubts Alexis Sanchez tug-of-war decided by money|
|Conte admits Pedro dived|
|Valencia tie down Torres amid Real Madrid, Barcelona reports|
|Bangladesh claim record win over Sri Lanka|
|Congratulations! Guardiola offers well wishes to United-bound Sanchez|
|Pele pulls out of London event amid conflicting health reports|
|Conte would be ´happy´ for transfer help|
|Kontaveit dumps Ostapenko out, Wozniacki battles through|
|Sanchez to United not done at all, insists Mourinho|
|Rafa sails through, Kyrgios books Dimitrov showdown|
|Emery refuses to indulge Neymar-Cavani penalty debate|
|Wozniacki battles past stubborn Bertens|
|Goretzka chose Bayern over England, Spain and Italy – Heynckes|
|BBBofC ready to lift Fury suspension|
|I would reject such players – Heynckes slams ´selfish´ Aubameyang|
|Kyrgios proves cool credentials to Will Smith in Tsonga win|
|Western Sydney Wanderers 0 Melbourne Victory 3: Barbarouses extends purple patch|
|Conte likes Dzeko but Chelsea have made no offer, says agent|
|Goretzka´s Bayern move good for Bundesliga, suggests Rummenigge|
|Root guides England home as Finch century proves in vain again|
|Walcott left Arsenal with his things in bin bags|
|Nadal breezes past Dzumhur in Melbourne|
|Schalke confirm Goretzka will join Bayern|
|Sergi Roberto renews Barca deal until 2022|
|Fernandinho seals extended Manchester City contract|
|Ceballos knee knock to be assessed after Real Madrid Copa win|
|O´Sullivan says snooker is ´weighted towards numpties´ as he repeats World Championship threat|
|Hamsik has no doubts over Napoli future|
|Corchia determined to repay Montella´s faith at Sevilla|
|Arsenal or Manchester United – who wins from the Sanchez-Mkhitaryan deal?|
|Black Caps survive Pakistan comeback to claim series sweep|
|Celtics lose without Irving as Cavaliers end skid|
|I can play against anyone, says 15-year-old Kostyuk|
|I would love to coach PSG – Mancini|
|Now an All-Star, Joel Embiid ´might have to pass´ on Rihanna|
|Merson: Mkhitaryan will be a sensation at Arsenal|
|Aussie debutant Carey replaces Paine for second ODI|
|Wins over substance for Varane and Real Madrid|
|Arsenal´s Giroud the answer for Chelsea, says Parlour|
|Rahm shoots 62 to lead CareerBuilder Challenge|
|Wenger: Sanchez exit won´t hurt like Van Persie|
|LeBron, Curry named captains for NBA All-Star game|
|Zidane hopes late Leganes win is turning point for Real Madrid|
|Magic´s Afflalo handed two-game ban for fighting|
|De Gea happy to delay Man Utd contract talks|
|Celtics guard Irving misses 76ers game with shoulder injury|
|LeBron James determined to work through ´very challenging´ Cavaliers season|
|Leganes 0 Real Madrid 1: Asensio´s late goal lifts pressure on Zidane in Copa quarter-final|
|Toulalan follows Gourvennec out of Bordeaux|
|Texans DE J.J. Watt showing positive signs with rehab|
|CC Sabathia likes the Yankees being a ´hated team´ again|
|UCI president wants Team Sky to suspend Froome|
|Dortmund´s Durm suffers torn ankle ligaments|
|Chelsea send Nathan to Belenenses on loan|
|Chelsea in talks over deal for Roma full-back Emerson|