Ole Gunnar Solskjaer was forced into that selection call after seeing Nemanja Matic ruled out with an untimely knock.
More injuries were sustained during a cagey contest at Old Trafford, with Ander Herrera, Juan Mata and Jesse Lingard forced from the field while Marcus Rashford battled through an ankle problem.
Solskjaer believes he has the depth in his squad to counter such problems, with the performance of McTominay against Liverpool highlighting the quality of cover at his disposal.
He has been likened to a midfielder from United’s past, with Sir Alex Ferguson often calling upon Scottish strength in that area as the Red Devils helped a reliable performer to five title triumphs.
Solskjaer said of his options on the back of a goalless stalemate: “I learned a lot about Scott McTominay, who I've been waiting to give a chance in a more attacking role, he can run into the box, is dangerous, he was a Darren Fletcher today for us.
“Absolutely fantastic, he's not played since Reading, that's six weeks ago, January 5.
“Andreas [Pereira], with the criticism he's had to come on and did fantastically. So I learnt a lot about the character of the team.
“That first half wasn't good enough with the ball, never seen us be so sloppy on the ball, giving easy balls away but then we got through it.”
Solskjaer also hailed the performance of his back four against a Liverpool side famed for their attacking threat, with Luke Shaw among those to earn plenty of praise after being charged with the task of containing the dangerous Mohamed Salah.
“Very happy with [the defence] and that's always the foundation, if you keep clean sheets and keep David [de Gea] not very occupied, we know we've got something going and teams have to be built from that foundation,” added the Red Devils’ interim boss.
“Victor [Lindelof] and Chris [Smalling] fantastic, Luke Shaw, that was his best performance under me.
“It's one of them things, you want him to go forward a bit more but Salah and [Sadio] Mane aren't bad, either, so we had to take that bit of caution.
“Even though you're never happy not winning a game this was a good performance.”
United, who will need to shuffle their pack again with so many players nursing knocks, are back in action on Wednesday against Crystal Palace at Selhurst Park.