The Scotland international midfielder endured injury struggles during his academy days and believes other clubs would have cast him aside
The 23-year-old midfielder is now an established part of the fold at Old Trafford.
A big break arrived for him in the spring of 2017, with Jose Mourinho offering a promising academy graduate the opportunity to see first-team minutes.
McTominay impressed his Portuguese coach and went on to become a regular before another change in the dugout was made.
Ole Gunnar Solskjaer has continued to keep faith with the Scotland international and he is now just five appearances short of reaching a century for United.
That is some achievement for man who concedes that he almost did not make it, with injury struggles as a youngster requiring the Red Devils to show considerable faith and patience in him.
Discussing his career path with Pro Direct Soccer, McTominay said: “I genuinely don’t think it’s sunk in.
“I think it’s something that I will look back on at the end of my career.
“It’ll sink in as a special time in my life and sometimes you need to reset and think about it. My family are very humble, they won’t let you get ahead of yourself. They are always pushing me behind the scenes.
“When I was 16, I was really small. I couldn’t get near the team and I was injured for two years in the youth team.
“When I look back on it, if I knew in my mind how difficult it is to get to here, I would have written myself off.
“If I was at any other football club, I wouldn’t have been a footballer.”
Injury struggles have remained an issue for McTominay at times since his step up into the senior ranks.
He missed 12 games with a knee problem last season, with an enforced spell on the sidelines allowing others to impress in his absence.
Solskjaer does now have fierce competition for places in his engine room, with there a wealth of midfield options at his disposal.
McTominay has taken in 11 outings this season, while helping Scotland to qualify for next summer’s European Championship, but is having to battle with the likes of Paul Pogba, Bruno Fernandes, Fred, Nemanja Matic and Juan Mata for recognition.