Reactions to the coronavirus pandemic have thrown world football into uncertainty. In the past 72 hours, a host of leagues joined Switzerland and Italy in suspending operations, including Spain, Portugal, Norway, Belgium, Denmark, Scotland and Holland, along with Major League Soccer in the USA. The Premier League soldiered on until Friday, when it announced that it, too, was shutting down. The same call was made by officials in France and Germany to shut down their domestic competitions.

Other leagues are opting to play behind closed doors. UEFA did that with some games this week, but have postponed all of next week's Champions League and Europa League games, with the fates of both competitions hanging in the balance.

Among the players and officials affected, Arsenal announced late on Thursday that manager Mikel Arteta tested positive for coronavirus. So did Juventus defender Daniele Rugani, on Wednesday, and Chelsea winger Callum Hudson-Odoi on Thursday. A host of clubs around Europe are adopting self-isolation protocols following presumed positive tests at Bournemouth, Leicester City and more.

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There is a very real possibility that Euro 2020, the second biggest football tournament in the world after the World Cup, could be canceled or postponed. Already, a number of friendlies scheduled for the international break later this month have been called off, while some of the qualifying playoffs for Euro 2020 are also at risk. (It's worth noting the other competitions still hanging in the balance across the globe, like the CONCACAF Nations League, Olympics and South America's signature Copa America, too.)

As the pandemic spreads, governments react and policies change, the simple truth is that we can only speculate as to what might happen next. But football authorities are working on scenarios and contingencies.

Here is an attempt to answer some questions you might have concerning the rest of the European season and beyond.

Q: UEFA say they are holding a video conference with stakeholders on Tuesday to discuss their reaction to the outbreak. What are they going to do with the European season and the Euros?

A: Well, that's why they're speaking to their stakeholders: the 55 member nations, representatives of the major European leagues, representatives from the European Club Association (ECA, the body representing the interests of clubs on the continent) and FIFPro, the umbrella organisation of players' unions.

UEFA are responsible for the Champions League and Europa League, but the situation varies around Europe, in terms of local regulations on containment and travel restrictions. They want to speak to them first before making any comprehensive decision. Until that point, they have gone with local decisions: so, for example, Paris Saint-Germain played behind closed doors against Borussia Dortmund on Wednesday, but Sevilla vs. Roma the next day was not played at all because of travel restrictions between Italy and Spain.

Q: Are UEFA passing the buck?

A: They would say that making decisions like this is well above their pay grade. It is the job of governments to decide what to do, based on advice from the medical community. If enough countries make it impossible to continue or if enough of their stakeholders tell them to stop, UEFA will stop, which is what they've done in postponing next week's Champions League and Europa League games.

When it comes to figuring out what to do with the rest of the season, the decision is too important to be made top-down. Equally, the advice UEFA has been given -- they've consulted with government/medical authorities in a host of countries including Switzerland, Italy, Spain and Germany, as well as the European Union and World Health Organization, the latter of which is based on Switzerland -- is that we'll have a clearer picture of the situation in the next three or four weeks and governments will, hopefully, have a better sense of when things might begin to return to normal. That is why most of the suspended national leagues have only been called off until early to mid-April.

Q: OK, but if you're suspending next week's games and the quarterfinals were originally scheduled for April 7-8 and April 14-15, you cannot play them until you sort out the Round of 16, so how are they going to cram everything in?

A: That's what they will try to figure out, but there is very little room to maneuver, not least because even if we somehow get the "all-clear" to resume play, domestic leagues will want to start up again and try to make up games, which means even more fixtures. One solution might be for the Champions League and Europa League to have single-legged quarterfinals and semifinals, either in a neutral venue or, perhaps, with the highest-seeded team playing at home.

Q: What if they don't get everything done in time for the Champions League final on May 30?

A: Then I guess we won't have a Champions League winner. They cannot postpone the final because Euro 2020 starts on June 12 -- unless, of course, they postpone Euro 2020, which you can bet will be on the meeting agenda next Tuesday.

Q: That would make sense, and if you are going to do that, it means you can also complete the domestic league seasons, right?

A: Yes, though that creates another problem. Namely: When do you play Euro 2020?

The obvious thing to do would be moving the competition to the summer of 2021, after next season, but that's not entirely straightforward. You'd have to scrap or reschedule the UEFA Nations League finals, as well as reschedule some World Cup qualifiers for Qatar 2022.

The women's European Championship is also scheduled for the summer of 2021, with England the hosts. As it stands, and assuming they keep the same dates (June 12-July 12) for the men's Euros, those competitions would overlap for a week or so, which is far from ideal. It would also impact the women's Euros in terms of logistics and marketing.

Then there's the inaugural expanded FIFA Club World Cup in China, which is scheduled to begin on June 17, 2021. At present, eight European teams will be involved in that. The rocky relationship between UEFA and FIFA could be a further obstacle if the calendar needed to be reset.

Q: OK, so what happens to the domestic leagues if they cannot complete the fixtures? Either because the situation does not improve or because it improves just enough for UEFA to finish its competitions, but the Euros still go ahead, which means the season cannot be extended?

A: It is another thing to be discussed on Tuesday.

Serie A, which has had to deal with this before everybody else due to the extent of coronavirus' spread in Italy, laid out three scenarios, all of them under the assumption that the Euros aren't moved.

The first is simply declaring the 2019-20 season vacant. There would be no winner in the record books, no relegation and spots in next year's UEFA competitions would be based on the league table as it is now. (Incidentally, if the Premier League went with this idea then Liverpool, who are 25 points clear, would miss out on their first title in 30 years.)

Another option is to simply declare the season over based on the league table. Those would be the final standings.

The third option is to have some kind of mini-league or playoff to determine the champions and European places at one end of the table, and relegation at the other, using some sort of formula to carry over points from the table. But that is contingent upon the situation improving to the extent that you have time to play games before the Euros, and we won't know that for a while.