Scotland Under-21 skipper Ross McCrorie will join uncapped defenders Andy Considine and Paul McGinn in Steve Clarke's squad for the Nations League double-header against Slovakia and Czech Republic.
Under-21 boss Scot Gemmill confirmed McCrorie would make the step up after the Aberdeen player scored in a 2-0 European qualifying win over the Czech Republic at Tynecastle.
The three players have been called up after national team manager Steve Clarke suffered six withdrawals in the build-up to Thursday's Euro 2020 play-off semi-final penalty shoot-out win against Israel.
Considine, 33, is a former Under-21 international who has spent his entire club career with Aberdeen.
The other two call-ups mean there will be two sets of brothers in Clarke's squad.
Hibernian full-back McGinn, 29, joins his former St Mirren team-mate John McGinn, while McCrorie, who can play in defence or midfield, joins his twin Robby, who is currently on loan at Livingston from Rangers.
Clarke's initial 26-man selection was severely hit by coronavirus issues and injuries earlier in the week.
Kieran Tierney and Ryan Christie were both ordered to self-isolate after Stuart Armstrong tested positive for Covid-19, while forward Oliver Burke and defenders Scott McKenna and Liam Palmer all pulled out injured.
Clarke's side overcame the late disruption to set up a Euro 2020 play-off final against Serbia next month after winning the national team's first-ever penalty shoot-out following their first extra-time in almost five decades.
And with Hampden Park games to follow on Sunday against Slovakia and the Czechs three days later, Clarke hopes to ease the burden on his players.
"We are going to have to come down, unwind a little bit," he told the Scotland media team.
"I am missing a few players through different circumstances, so we are going to have to have a look and get some players to join us to boost the squad.
"It was a big effort over 120 minutes for a lot of the players and it's going to be almost impossible for them to play the next two games, a full 90 minutes.
"There is a little bit of thinking to do for the coaches and hopefully we come up with the right formation for the next two games."
The victory over Israel was tense and tight, with Scotland having the better of the scarce chances but Israel also enjoying some decent spells of possession.
However, David Marshall's penalty stop from Eran Zahavi and Kenny McLean's winning kick extended Scotland's unbeaten run to six matches.
There remains obvious room for improvement performance-wise, but Clarke pointed out that results would help that gradual process.
"Another game where we come out victorious," he said.
"We are trying to build something, and I think people maybe underestimate that a bit.
"We are trying to build and slowly, slowly you have to build character, you have to build confidence, you have to build quality. That will come, the more results you get, the better we will become."