Gordon Strachan left the 28-year-old out of the squads that will face Czech Republic and Denmark later in the month.
The 28-year-old - who has eight international caps - was left out by Gordon Strachan, with the former Celtic boss instead picking Andrew Robertson and Kieran Tierney for the games against Czech Republic and Denmark towards the end of this month.
But while McKay admits that an argument could be made that Strachan's decision was justified, he insisted that the Gers skipper had done enough to be recalled to the side.
"I think the way Lee has played this year, you couldn't say he didn't deserve it. He's been doing it consistently in every game and really leads by example," he told The Scottish Sun.
"You could argue the opposition aren't as good but lower-league teams have shown they can beat the Premiership teams.
"It's an argument you'll never win because there are two sides to it. But he was in the squad when he was in the top flight and he hasn't changed as a player since."
While Robertson and Tierney's age means that they have the potential to be battling for the left-back slot in Scotland's team for many years to come, Wallace's form has been hugely impressive this season, even if the quality of sides he has come up against has often not been as strong as the teams in the Scottish Premiership or in the Championship where Robertson has been excellent for Hull City.
He has helped Mark Warburton's men concede just 18 goals throughout the league campaign, which has meant that they boast the best defence in the division.
And he has also been a threat going forward. His seven goals means that only three players have scored more times in the league, and he has also contributed four assists.
And with promotion to the top flight now looking inevitable for the Gers, he will be hoping to maintain that form as it may give Strachan less reason to leave him out of future squads.