For the first time in 22 years, the year's Grand Slam roll of honor will not feature any of the "Big Three "after Novak Djokovic suffered his earliest US Open exit since 2006.

The 24-time major winner's stunning third-round loss to Alexei Popyrin left the Serbian star facing a season without a Slam title for the first time in seven years.

"I played some of the worst tennis I have ever played," admitted a crestfallen Djokovic after his title defense in New York came to an abrupt end at the hands of his 28th-ranked opponent.

It also sparked questions over the 37-year-old's long-term future in the sport, and the endgame for tennis' golden generation of Djokovic, Rafael Nadal and the retired Roger Federer.

When Federer captured the 2003 Wimbledon title, it was the first of 66 Slams won by the Big Three out of the 84 played up to this year's Wimbledon.

Federer retired in 2022 with 20 majors.

Nadal, now 38 years old, has 22 Slams, the most recent of which came in 2022 when he swept to a 14th French Open.

A succession of injuries limited the Spanish star to just four matches in 2023, when he won just once, and 19 this year with 12 victories.

This season, he was defeated in the first round at Roland Garros for the first time in his career, before skipping Wimbledon.

Nadal hasn't played a singles match since losing to Djokovic in the second round of the Olympics.

He is scheduled to return at the Laver Cup in Berlin next month, and, with his ranking having slumped to 154 in the world, there will be inevitable speculation that he will follow Federer's example and use that event to bow out.

Djokovic, 37, holds a men's record of 24 Grand Slams, but remains frustratingly short of breaking the all-time tie he shares with Australia's Margaret Court.

If he were to achieve that goal at the Australian Open in January next year, he would be the oldest Grand Slam champion of the modern era.

"I have to draw the line," said Djokovic. "You're just angry and upset that you lost and at the way you played, and that's it.

"But, you know, tomorrow is a new day, and I will obviously think about what to do next."

Djokovic's roller-coaster year has seen him lose his Australian Open title to Jannik Sinner, who also ended the Serb's run as world No 1, a lofty status he had enjoyed for a combined 428 weeks.

Carlos Alcaraz, 16 years his junior, succeeded him as French Open champion after Djokovic withdrew from his scheduled quarterfinal with a knee injury that required surgery.

Alcaraz then blew the Serb off the court to defend his Wimbledon crown.

Djokovic quickly avenged that loss by claiming Olympic gold in Paris, which he described as his "greatest achievement".

The issue for Djokovic, who turns 38 next May, is that his aura of invincibility has crumbled.

Popyrin was so unsurprised by his victory on Friday that he described his recent Montreal Masters triumph as being "way bigger" than defeating a player widely regarded as the greatest of all time.

For Djokovic there is a crumb of comfort in knowing that, at the end of a long season, the US Open often throws up surprise winners.

Since 2000, there have been 14 different men's champions at the tournament, and no man has won the title back-to-back since Federer claimed his fifth straight US Open in 2008.

Djokovic and 2022 champion Alcaraz, who was also knocked out in the second round this week, appeared drained from their emotional Olympics experience.

Both admitted that their preparations for New York could have been better, a factor not lost on his rivals.

"If I did what he did after a gold medal, I'm just staying in Serbia, chilling, drinking like crazy," said US star Frances Tiafoe.

"That's why he is who he is, right? I really like that dude. Yeah, man, 37, want to come back out here? That's insanity, but hey, man, to each his own."

AFP