Days after a handful of the world's leading tennis players hugged and high-fived on court in front of packed stands and partied together in carefree fashion some - including world number one Novak Djokovic - were struck down by the COVID-19 virus.
As a cautionary tale, it could hardly be more stark.
For while the images from the Adria Tour exhibition tournament in Serbia and Croatia were no doubt a fillip for some fans starved of top-flight tennis action, the organisers also tempted fate with the lack of precautions.
Though the players were not breaking government protocols during the tournament, which was organised by Djokovic, it highlighted the risks of athletes from different countries mingling without adhering to what have become social distancing norms.
Few were, therefore, surprised when Djokovic contracted the virus with Bulgarian Grigor Dimitrov, Croatia's Borna Coric and Viktor Troicki having already tested positive after playing in his Balkan event.
Also Read: Novak Djokovic's Adria World Tour Has Given Tennis a Bad Name: Andy Murray Hindsight offers clarity, but organisers of the world's biggest tournaments say they will not make the same mistakes as they reopen the sport and seek to keep the players safe.
"There were a fair few learnings that have come out of that (Adria Tour)," Tennis Australia's (TA) Chief Operating Officer Tom Larner told Reuters.
"And whilst, certainly the whole event was actually really well-intentioned in terms of raising money for charity, the execution was clearly not great, as were the processes in place."
Australia had successfully curbed the virus spread but a double-digit increase in new cases recently has triggered fear of another wave due to apparent community transmission.
TA gave a glimpse of the biosecurity protocols that could be in place for next year's Australian Open while announcing measures for the domestic UTR Pro Tennis Series, which will be played at closed stadiums.
Players would have to bring their own towels and will be encouraged to shower off-site. On-court personnel would be limited to an umpire, minimal line judges with no ball-kids.
NO SPECTATORS First up, though, will be the U.S. Open, scheduled to be held in New York from Aug. 31. Organisers have come under fire, including from Djokovic, who initially called their measures "extreme". They will now feel vindicated.
"This situation is exactly why we have created a comprehensive health and medical plan... that was approved by New York State," USTA spokesman Chris Widmaier told Reuters.
"The creation of a controlled U.S. Open environment, including official hotels, transportation, food, medical and safety protocols, enables us to mitigate potential risk, and appropriately respond to any issues."
The U.S. Open will have no spectators, there will be limitations on players' entourage and everyone must wear masks when onsite unless practising or competing. Testing will be conducted before travelling to the United States and at least once per week along with daily temperature checks.
New York City has witnessed an easing of lockdown restrictions in recent days but residents have been asked to follow social distancing norms and cover faces in public.
Restaurants and bars began offering outdoor service and many retailers started to allow patrons back into their stores.
Serbia introduced a state of emergency soon after the pandemic broke out, including daily curfews for 12 hours, but gradual easing of measures saw 25,000 fans flock to a soccer derby between Belgrade rivals Red Star and Partizan on June 10.
A sellout crowd of 4,000 attended both days of the Belgrade leg of Djokovic's tournament, staged at his tennis centre by the Danube River.
Croatia, where the tournament's second leg was held in Zadar, still had social distancing norms in place and the Visnjik tennis complex, with a capacity of 9,000, hosted half as many spectators.
It did not stop Djokovic and his fellow players from playing basketball there, images of which were jarring to many as the majority of the world continued to battle the virus.
Djokovic, who heads the players council of the men's ATP Tour, said he was wrong and "deeply sorry".