His performances at the heart of the Red Devils midfield have drawn praise from his manager Jose Mourinho as well as the fans.
McTominay can potentially play for a number of national teams due to his heritage and rather cordial 'tug-o'-war' ensued over his allegiance in recent months.
Goal brings you all you need to know about the midfielder's international career options.
What national team does Scott McTominay play for?
FIFA's eligibility rules allow a player to qualify for a national team if, in addition to having the requisite nationality, they were born on the territory of the association or if any of their parents or grandparents were born on that territory.
The Red Devils midfielder was born in Lancaster so is eligible to play for England, but his father is from Scotland and thus he is also eligible to represent them.
The issue of which national team the 21-year-old would play for intensified in recent months following his breakthrough into the Man United team, where he has partnered Nemanja Matic ahead of Paul Pogba.
Back in February, his manager Jose Mourinho advised McTominay to follow his heart and choose to play for the national team he feels represents who he is, while former Scotland boss Craig Brown suggested that Alex Ferguson may also have had a word.
The midfielder, who attended Scottish training camps as a youth and is on record saying that he is "more Scottish than English", was evidently swaying towards Scotland, but the English FA made overtures to him nonetheless.
Reports at the beginning of March indicated that both England manager Gareth Southgate and newly instated Scotland boss McLeish had held meetings with McTominay.
And just a number of days later, on March 4, the Times revealed that he had settled on playing for Scotland. He was subsequently included in McLeish's panel on March 12.
Can Scott McTominay still play for England?
Yes. Despite being called up to the Scotland team for the games against Costa Rica and Hungary McTominay could still ultimately opt to play for England, even if it now appears unlikely.
According to FIFA's national team eligibility rules, only a senior cap in a competitive game is enough to irrevocably bind a player to a particular association.
Scotland's upcoming matches are both friendly encounters and not games in official FIFA competitions - such as qualifiers - he will not be deemed as 'cap-tied' to Scotland if he plays.
Since McTominay has not represented any national team at youth level, Scotland will be considered his first nation, but, until he plays in a senior competitive game, he is allowed to make a request to switch association.
Players who are eligible to represent more than one national team within the eligibility rules can only make such a request once.
Since FIFA altered the rules to remove an age limit on players making a change of national association in 2009, there are plenty of examples of players who have played for two nations at senior level.
Others include Jermaine Jones, who played three times for Germany before switching to the United States, while Nacer Chadli played for Morocco once in 2010 before opting to play for Belgium, the country where he was born.