Dan Coles, 36, a 2015 World Cup winner, was one of four New Zealand players scheduled to call it a day after this tournament along with Sam Whitelock, Brodie Retallick and 34-year-old scrum half Aaron Smith.

Meanwhile, South Africa, winners for a fourth time, will be bidding farewell to their 37-year-old number eight Duane Vermeulen.

England, widely discounted but eventually only a point adrift of the eventual winners in the semi-final, will lose the services of their former captain, Courtney Lawes, while prop forwards Dan Cole and Joe Marler are expected to announce their own retirements.

Long-serving scrum half Ben Youngs will also be ending his career, while that also looks likely to be the policy of Argentina’s 39-year-old prop Francisco Gómez Kodela.

Ireland, who can always say they beat the world champions in France, will lose captain Jonathan Sexton and and wing Keith Earls; Wales backs Leigh Halfpenny and Dan Biggar have also quit, as have French forwards Uini Atonio and Romain Taofifenua.

The likelihood is that most of these players will remain retired. But don’t bet that there won’t be one or two who return to the field of their remembered dreams.

When you have performed at that level, it’s hard to come back down to normal altitude.

Such was the case with the seven-times Super Bowl winner and celebrated quarter-back Tom Brady, who retired from the National Football League after 22 seasons - and returned after 40 days.

Admittedly, he spent only one more season with the Tampa Bay Buccaneers before announcing on February 1 this year that he really was leaving.

Another massively successful American sportsman, swimmer Michael Phelps, took a similarly switchback route, announcing his retirement after the 2012 Olympic Games in London, where he had raised his collection of Olympic gold medals to 18.

"I'm done. I'm finished. I'm retired. I'm done,” he said. "No more."

Ah, but there was more. Two years later he made a comeback and two years after that added five more golds at Rio 2016 before really retiring as the most decorated Olympian of all time with 28 medals.

Phelps’s London 2012 assertion recalled that uttered at Atlanta 1996 by exhausted British rower Steve Redgrave after he had won the coxless pair with Matthew Pinsent to earn a fourth Olympic gold: "If anyone sees me go anywhere near a boat, you’ve my permission to shoot me."

Thankfully no one took Redgrave up on that offer and four years later in Sydney he added gold medal number five with another fabled victory, this time in the four along with Pinsent, Tim Foster and James Cracknell. 

American basketball icon Michael Jordan called it a day in 1993 aged 30, explaining that he had lost his "sense of motivation".

In 1995 he was back in the National Basketball Association with Chicago Bulls, with whom he won three more Championships before retiring in 2003.

In the realm of tennis, retirement worked out well for Belgium’s Kim Clijsters, who left the courts at the grand old age of 23 in 2007 because of mounting injuries and diminished desire to carry on.

At that point she had one Grand Slam win to her credit - the 2005 US Open.

Two years later, a married woman with a daughter, Clijsters returned to the game and added two further US titles - winning the first of them as an unranked player in just her third tournament back - and an Australian Open, en route to becoming the first mother to become world number one.

Björn Borg was 25 when he walked off the main court at Flushing Meadows in New York City after losing the 1981 US Open final to John McEnroe for a second successive time and kept on going, all the way to the airport, where he flew up and away from his fabled tennis career.

No award ceremony. No press conference. No more tennis - "definitively."

Borg had been a Grand Slam champion at 18, having claimed the French Open title he would go on to win five more times just a couple of weeks after his birthday.

Two months before he walked away from the game Borg’s record of five consecutive victories at Wimbledon came to an end as McEnroe, overcome in five sets during their epic 1980 final in SW19, finally cracked it with a 4-6, 6-2, 6-4, 6-3 win.

But, as Borg revealed to Tim Adams in a 2007 interview with The Observer, he had felt the tipping point occur in the Wimbledon final a year earlier, when he was one set away from what will always be regarded as his most epic victory.

Borg surrendered seven match points in the fourth set before McEnroe levelled the match at 2-2 by winning the tie-break 18-16. That was when he felt he could be beaten…

"Watching myself losing that last point, 18-16, I can feel that walk back to the chair now as if it was yesterday," he told Adams. "That was the toughest moment in my tennis career, that walk.

"I knew John thought he would win the match. I thought he would win the match. I don't know how I regrouped. If he had broken me in the first game of the fifth set I would have lost, but I won from love-30 and then I played just unbelievably well, hardly lost a point on serve and won the match. That was the strongest set, mentally, in my tennis career."

But the seed of doubt had been sown in that moment.

When Borg lost his Wimbledon title the following year, there was another unwelcome revelation for him.

"I felt I was much the better player that day," he added. "But I just wasn't so focused. And when I lost what shocked me was I wasn't even upset. That was not me: losing a Wimbledon final and not upset. I hate to lose. It was the same at the US Open. Losing to John again I was relieved the match was over."

Borg played sporadically thereafter before announcing his definitively definitive retirement in 1983.

Bizarrely, in 1991, something stirred deep in his soul and he turned up at the red clay courts of the Monte Carlo Country Club once again equipped with an old-style wooden racket and an inexplicable desire to take part in the annual championships despite having had no practice or significant training.

He lost his first match. Over the course of the next two years, in similar circumstances and with the same equipment, he lost eight more without winning a single set.

That was a humiliation for one of the greats of the game. But he has got over it.

Miscalculating a comeback can have more serious connotations if you are a boxer, however.

When George Foreman hung up his gloves in 1977 after a devastating loss to Jimmy Young it was three years after he had lost the world heavyweight title to former champion Muhammad Ali, whose description of the fight in Kinshasha in Zaire as the "Rumble in the Jungle" endures.

Foreman remained out of the ring for a decade before returning at the age of 38. In 1994, aged 45, he won the World Boxing Association and International Boxing Federation titles by defeating 25-year-old Michael Moorer. He became the oldest world heavyweight champion in history.

For the incomparable Ali, however, the retirement game worked out less well.

Having regained the world title in Kinshasha, Ali lost it in 1978 after underestimating the inexperienced Leon Spinks, who won on a split decision. Later that year Ali won his title back with a unanimous decision in the re-match.

He thus became the first man to win the world title three times; and shortly afterwards, on July 27, 1979, Ali announced his retirement.

The end.

If only it had been.

The following year he decided to try and become the first man to win a world title four times with a bout against the new champion, Larry Holmes - who was reported to have not wanted to fight Ali as he knew he had "nothing left" and that the contest would be "a horror."

It was. It went to 10 rounds before Ali’s corner threw in the towel.

Despite pleas from all sides to retire, Ali went on for one more fight, in 1981, when he met Trevor Berbick in Nassau and lost after 10 more gruelling rounds.

Many observers believe these last two fights contributed to his later Parkinson’s syndrome.

Sometimes, in sport as in life, it is most important to know when to say that sad but necessary word: Goodbye.