Novak Djokovic's deportation from Australia due to his coronavirus vaccine status may be the portent of worse things to come for the Serbian tennis superstar.
The fall-out from the 34-year-old's very public stand-off with the Australian government raises questions not just about his bid for a record 21st Grand Slam title -- it could affect him in many other ways.
AFP Sport picks out three potential consequences:
Novak Djokovic has always made much of his love of the history of tennis and is keenly aware of his place in it, although he said last year he found it "difficult to understand the magnitude of (my) achievements . . . While I'm still an active player."
He made a bit more history at the Australian Open in being the first tennis world number one to be deported and the repercussions of his absence could be monumentally costly for him on court.
His absence could see Rafael Nadal secure what the Serbian wanted to achieve in Australia -- an unprecedented 21st Grand Slam singles crown.
If 35-year-old Nadal falls short, Djokovic could lose out in another way -- his record two-year reign as world number one could be ended if either Daniil Medvedev or Alexander Zverev win the Australian title for the first time.
Medvedev -- who denied a tearful Djokovic a Grand Slam sweep in 2021 by beating him in the US Open final -- came close to achieving that last year.
Djokovic has made no secret that his friend Medvedev is his most likely successor.
However, when he expressed that view after beating the Russian in the Paris Masters last November, he probably envisaged rather different circumstances.
"I'm sure he's going to get it eventually, and when he does, it's completely deserved," Djokovic said then.
Djokovic has earned an estimated $150 million during his stellar career.
However, the $30 million he earned from sponsorship deals last year -- according to Forbes magazine -- may not be so sacrosanct as sponsors take stock of the situation and assess the potential damage to the image of their star and to them.
Djokovic's Lacoste contract was his most lucrative, valued at around $9 million by several American media outlets.
The clothing firm bearing the emblem of a crocodile -- the nickname of its founder, French tennis legend Rene Lacoste -- indicated it may bare its teeth in talks with Djokovic.
"As soon as is possible we will be in touch with Novak Djokovic to talk about the events in Australia," read a Lacoste statement.
Djokovic, though, can take heart from the experience of a fellow sporting superstar and anti-vaxxer Aaron Rogers.
The Green Bay Packers quarterback lost only a minor sponsor last year, who took a dim view of both his anti-vaccine stance and his claim that his critics were "a woke mob".
Slam doors shutting?
Nadal winning the Australian Open would require Djokovic to win two more Grand Slam titles to be the sole holder of the record number of singles titles. The Spaniard has only won the Australian crown once and lost the four other finals he has contested in Melbourne.
With doubts over whether Roger Federer -- the third member of the triumvirate that are level on 20 titles -- can add to his haul when he returns from yet more knee surgery, Djokovic was looking good to achieve yet another record.
However, the very reason for his deportation from Australia could change the complexion of his future career because Covid is not going away anytime soon and nor will the regulations regarding vaccination made by ever cautious governments.
Wimbledon would appear the only tournament he can confidently think of playing in after the French Open doors closed on him on Monday.
The French sports ministry said a new vaccine pass, approved by the parliament on Sunday, "applies to everyone, to volunteers and to elite sportspeople, including those coming from abroad, until further notice."
The US Open would also appear to be a no-go area for the Serb according to the stringent vaccination rules currently in place in New York.
"It is an objective, yes, to prove that I can break all the records," Djokovic said last November. "I'm very motivated to carry on."
Whether the damaging Australian saga has sapped that inner drive will be hard to gauge but for the moment that Grand Slam record must seem further away than ever.