The 20-year-old, who made his debut against Arsenal earlier this month, was one of the nine academy products that featured against Sam Allardyce’s side.
He enjoyed a strong first start for the senior side, displaying plenty of eagerness to move the ball forward and find space wherever he could.
And McTominay, speaking after the game, revealed that Mourinho told the youngsters to simply enjoy the occasion.
“He was just saying be calm, be composed and go and play your normal game and enjoy it,” he said. “Obviously it was a brilliant experience today with all the young lads making their debuts and having a positive result in the end. We wanted to go out and win the game and that is what we did.
“It was an unbelievable feeling going out there in front of 75,000 people – the biggest crowd that a lot of our lads have played in front of. You just have got to embrace that whenever you go out there and play like it is a normal game, and go and grab the opportunity.”
“If you want to be a top, top player, you have to play in pressured environments in these games. Throughout my career I want to be playing in the Premier League so that’s the most important thing for me, to get as many of these games as I possibly can and hopefully push into the first-team.”
The prospect of seeing the class of tomorrow feature at Old Trafford, something first canvassed by Mourinho a few weeks ago, prompted a mixture of excitement and apprehension. How would such a plethora of youngsters fare in the Premier League? Could it be a step too far for some of these boys?
It quickly became clear that, actually, in terms of Man United’s Premier League inertia, this was exactly what they needed. That first half was a reminder of what this club has always placed faith in youth: United were quick, bold, fearless going forward and clearly keen to express themselves. Such an injection of exuberance, held together by the brilliance of Paul Pogba in midfield, served as a powerful reminder of what the academy continues to produce.