It's going to play havoc with this season as well.
Absolutely, every time there is an international break you have to pray none of your players play on a national team that has an outbreak. Let alone the travel through airports around the world. Teams could be down multiple players for a few matches.
Tsimikas who tested positive while away with Greece gets sent home on Saturday, all Greek players are tested before the match against Kosovo and are all negative. Game is Monday, on Tuesday another Greek player Limnios tests positive. Now all club teams who have Greek players will have to isolate those players and test them again and even then there is no guarantee as with the above case it took a few days for the virus to be detected.
This could just as easily happen to England, Italy, any other national team. It already has happened to France and Spain (Not sure if Adama had contact with the rest of the squad?) I'm interested to see if any other French players test positive in the next few days. It's going to derail some unlucky club teams at one point or another.