Just before Wimbledon fortnight begins this June, his trophies will be held up for inspection by a professional auctioneer at Bonhams in London. Both Borg and Bonhams are hoping that a little of the magic of Wimbledon will be sprinkled over the event and will yield him close to £500,000. The trophies are tipped to make around £300,000 while the Donnay racket with which he defeated John McEnroe in a five-set final in 1980 should bring in a further £20,000.
"You're a long time retired," Ian Botham said as he came to the end of his cricket Test career. Most fans imagine that their heroes, even if they are no longer performing, at least have their trophies to keep them warm. Some English footballers have sold their World Cup winners medals, with Alan Ball collecting £164,000 last year, but most prefer to gaze at them into their old age.
So why is a man who enjoyed such phenomenal success as Borg having to sell off the family silver? "He was taken for a big ride," said Richard Evans, the tennis writer and McEnroe's biographer. Evans recalled seeing Borg with some of his then business associates in Monte Carlo when everyone was drinking his champagne before flying first-class for a week in Japan. "He was much too trusting. He made bad choices which led to bad luck. Most tennis players of his ilk, with the exception of Roscoe Tanner who is now in jail, have gone on to become very successful millionaires."
Borg is unusual for someone who was so successful at tennis not to have made a lasting fortune. His successors playing the game now are also able to cash in on sponsorship deals and prize money of which even someone as successful as Borg could not have dreamed.
"He's not a stupid guy at all," said Evans. "He's intelligent and amusing and I have to say I'm surprised that he's having to [auction his trophies.] But he's living in Stockholm and in Sweden you get taxed out of existence so I suppose that may be the reason."
Borg retired from tennis in 1983 at the early age of 27, having no further appetite for the game and exhausted by the demands that had driven him to 62 tournament victories, including five Wimbledon and six French Open titles. He made an ill-fated attempt at a comeback in 1991, then made a more successful and dignified return as part of the over-35s tour playing in the Honda Challenge at the Albert Hall in 2000.
But it was away from the court that his bad decisions were to dog him. Bjorn Borg Design, the company he had helped to found and to which he had given his name to market luggage, sportswear and aftershave lotion went bankrupt in 1989 with heavy losses. The Swedish government pursued him for $40,000 in back taxes, threatening to make him personally bankrupt and he faced bankruptcy again in 1997 before being bailed out as creditors pursued him for around $1m. His more recent business ventures, selling Bjorn Borg underwear, shoes and glasses, have been happier experiences.
His personal life, with three marriages, two divorces, two children and two stepchildren, has carried its own expenses. His 15 years as a resident in Monte Carlo may have been undertaken on the advice of tax lawyers but it had the effect of removing him from Sweden and his roots. Now that he is involved again in tennis on a much more regular basis, coaching young Swedish players, he seems much more contented, according to commentators.
The image of Borg on court was of the ice-cool Swede. Five years ago he told the Guardian: "Sometimes I needed to let my feelings loose. When I got back to my hotel after matches I had to react with my emotions."
What emotions he may have this June when the trophies that he captured and the faithful racket that took him to victory are handed over to a stranger will be harder to quantify.
But an auctioneer's hammer will never be able to dispose of the memories of Borg's days of high summer.
How other players fared
Roscoe Tanner
Whatever problems Borg may face, they hardly compare with those of his one-time rival, the big-hitting Tanner who was sentenced to two years jail in January for parole violation on a grand theft conviction. Tanner, known for his speed on court, made an equally nifty departure from the US after facing allegations of grand theft, forgery, passing dud cheques, making false statements and failure to pay child maintenance. When the authorities caught up with him in Germany he was jailed for six weeks while extradition proceedings were completed. He still faces massive debts despite having made more than $2m while playing.
Vitas Gerulaitis
"What do you do when your name sounds like a disease?" he mused wryly on the opportunities afforded to ex-sports stars. He retired in 1986 and went into celebrity tennis, taking part in an ill-advised Battle of the Sexes competition with Bobby Riggs against Martina Navratilova and Pam Shriver. The men lost. He died aged 40 in a freak carbon monoxide poisoning accident in Long Island in 1994.
John McEnroe
Now 47, another of Borg's great rivals has perhaps been the most successful of his contemporaries in parlaying his tennis skills into off-court financial success. Apart from his sponsorship deals, commentary work and tennis as a veteran star, he has more than 40 screen credits to his name, making television or film appearances in everything from Mr Deeds to Frasier. All of which has helped him to estimated lifetime earnings of more than $100m (£57m). Tennis retains its lure: this year he returned to the pro tour winning the doubles at the San Jose tournament with Jonas Bjorkman.
Arthur Ashe
A Wimbledon winner in 1975 but perhaps almost as well-known for his human rights work, he became a journalist following retirement as a commentator and a magazine columnist. His glittering post-tennis career was interrupted when he contracted HIV through a tainted blood transfusion during heart surgery. He died in 1993.
Ilie Nastase
Now 59, the Romanian who admitted that "I am a little crazy but I try to be a good boy" has managed to use his celebrity to good effect. He has had two novels published and nearly had a career in politics, running for mayor of Bucharest in 1996. He lost.
Jimmy Connors
Now 53, the winner of eight grand slam titles, carried on playing till he was 39 even although at one stage he had dipped in the rankings to 936. He made $6,614,000 in his professional career. Now a sought-after commentator. Currently making a tennis DVD with Boris Becker, Chris Evert, Anna Kournikova and Andy Murray.
Buster Mottram
The last British player before Andy Murray to make into the world top 100 as a teenager, his far rightwing views made him an unattractive sponsorship option. He tried to make it as a Conservative politician, but six constituencies decided they could do without his service.