Celtic and Arsenal are both seeking clarification from the Scottish authorities after losing players for big games following self-isolation orders.
Ryan Christie and Arsenal left-back Kieran Tierney have both been instructed to self-isolate for 14 days after their Scotland and former Celtic team-mate, Stuart Armstrong, tested positive for Covid-19 while on international duty.
Christie and Tierney both tested negative and have insisted they complied with social-distancing guidelines.
But Lothian Health Protection Team identified the two players and two members of the Scotland backroom staff as close contacts of Armstrong.
The pair will miss Scotland's triple header, including Thursday's Euro 2020 play-off semi-final against Israel, along with huge club games on October 17. Christie will sit out the visit of Rangers while Tierney will miss the Gunners' clash with Manchester City.
A Celtic statement read: "Following (Wednesday's) news regarding Ryan Christie, he has reiterated his adherence to all relevant protocols while on international duty.
"In light of this, Celtic confirmed that it aims to open dialogue with the Scottish Government and other authorities to fully understand the self-isolation procedures for those players who continue to deliver negative test results, as Ryan has."
Christie added: "I am so disappointed by the events and the potential effects this could have on my country and club.
"As I have operated within these protocols for such a long time now, I am well aware of all the rules and social distancing from team mates has become the norm and something I have observed.
"The situation is very frustrating, particularly as I don't believe I have done anything wrong."
An Arsenal statement read: "Our medical team have confirmed that Kieran was socially distant at all times from the player who tested positive and has broken no rules regarding Covid-19 protocols.
"We are currently seeking further advice and clarification of the details."
Tierney added: "I'm so disappointed and frustrated to be in this situation. I have adhered to all regulations and made sure I was socially distancing from my team mates in the hotel. I've also tested negative.
"I know Arsenal and the SFA are now in discussions with the Scottish authorities to gain a further understanding."
The Christie blow came less than 24 hours after news that Celtic's main goalscorer, Odsonne Edouard, had tested positive for the coronavirus while on France Under-21 duty.
The 22-year-old will have to self-isolate for at least 10 days, making him a major doubt for the Glasgow derby clash.
Some fans' reaction to the double blow prompted Celtic to respond to calls for their players to be withdrawn from international duty.
Celtic wrote on Twitter: "The club will always do everything possible to protect the health and wellbeing of our players, but the release of players for international matches is governed by the FIFA regulations."