Typically symptoms show within 5 days. Two weeks is the farthest range for symptoms to start showing.
But I think there is more of this to come. These are the kinds of reactions we'll be getting from even individual diagnoses, and you know there are going to be many more of these in the comings days and weeks.
Now if you want to contemplate worst case scenarios, the league and club managers will put heads together and make declarations. Perhaps the most logical would be that Liverpool are clearly champions of the 2019-20 Premier League season. None of the other 19 clubs should challenge that.
Prize money would likely be mitigated if the season is cut short. Fine by me.
For the sake of congruence, with issues related to Euro qualification, promotion and relegation, you might see some very different solutions, including mini-tournaments involving certain teams, perhaps playoff games involving home and away setups. Unprecedented things in league play but something that might be attempted given there are big questions to answer and in that worst case scenario, only a limited time frame (after some longish lockdown period) to answer them.
European competitions might have to do the same thing, say a one-week tournament for the quarterfinals, semifinals and final, with all knockout games at a neutral venue and no home matches for anyone.
If thjs all sounds rather American, there is no question any solution after a long shutdown would be imperfect, but I think something like this would be attempted rather than just binning everything.
The one thing I'm absolutely sure of is that Liverpool are champions of English football in 2019-20 and nobody should even think of saying otherwise.