Stuart Armstrong, Kieran Tierney and Ryan Christie will all miss Scotland’s Euro 2020 play-off semi-final against Israel on Thursday after the former tested positive for Covid-19.
Armstrong was the only member of the squad to return a positive test.
But Arsenal defender Tierney and Celtic attacker Christie must self-isolate for 14 days from Tuesday after being identified as close contacts.
They will also miss Nations League ties with Slovakia and the Czech Republic.
Head coach Steve Clarke also revealed that defenders Scott McKenna and Liam Palmer, and attacker Oliver Burke, will be absent for all three matches through injury.
Furthermore, Christie will be unavailable for Celtic’s Old Firm meeting with Rangers on 17 October, while Tierney will miss Arsenal’s visit to Manchester City the same day.
Celtic confirmed they intend to speak with the Scottish government to “fully understand the self-isolation procedures” for those who test negative.
And Christie says he does not believe he has “done anything wrong”, having followed social distancing rules.
In a statement, Arsenal said that Tierney was “socially distant at all times” from Armstrong and had not breached any Covid-19 protocols.
The Premier League club said they were “seeking further advice and clarification of the details”.
“I’m so disappointed and frustrated to be in this situation,” Tierney added. “I have adhered to all regulations and I’ve also tested negative.”
Southampton midfielder Armstrong tested negative after arriving at the Scotland camp on Monday.
However, a subsequent Uefa test came back positive, meaning he must self-isolate for 10 days from Tuesday.
“While this is obviously disappointing news the most important thing is the health and safety of the individuals involved and the wider group,” said head coach Clarke.
“We have informed the respective clubs from whom we have borrowed the players and backroom staff and we now have to prepare for a huge match ahead tomorrow [Thursday].”
Scottish FA chief executive Ian Maxwell confirmed that the rest of the squad have “returned two rounds of negative tests” and will continue to prepare for the upcoming matches, with Slovakia visiting Hampden on Sunday and the Czechs on Wednesday.
A team masseur and a physiotherapist are also self-isolating after being deemed as close contacts by the Lothian Health Protection Team.
‘Clarke won’t panic’ – analysis
Former Scotland manager Craig Levein speaking on Scotland’s The Nine
I don’t think you hit the panic button, that’s for sure. It just goes with the territory, I’m afraid.
I think Christie, Tierney, McKenna might have started the match, maybe Palmer, so there’s four changes that have to be made.
He’ll have to get over the initial disappointment of losing some of his best players.
I think they’re capable of getting through, they need certain players in the team to play well on this occasion, Lyndon Dykes is one who can make a difference in the match.