'Like that every week': McTominay wants Man Utd to show consistency
McTominay was United's hero with a brace in the vital victory at Old Trafford on Wednesday.
But the Scotland midfielder said the result would only be significant if his sixth-placed team produced that kind of performance more regularly.
United's difficult start to the season had hit a new low last week when they blew the lead in their Champions League draw at Galatasaray, then slumped to a lacklustre loss against Newcastle.
"We have to find that balance between us where we try and do that every single week," McTominay said.
"I felt like that was a game where we had to come out and show to the fans that we have full focus on this game, we want to play well and give a reaction.
"It has to be like that every week, though, which is something that when I was in the dressing room, there was players speaking about it.
"It can't just be one game where we need to show a reaction. It has to come out and show that every week."
United's difficult start to the season had put a spotlight on Ten Hag's relationship with his squad amid reports several players had grown disillusioned with his intense training sessions and hardline discipline.
Ten Hag has denied those claims and United's players certainly appeared to be on his side on the evidence of their hard-fought win against Chelsea.
Aware of the negativity around Old Trafford this season, McTominay said he was grateful to the United fans for "sticking with us throughout anything that goes on at this football club".
"We know the fans are extremely demanding and so are we as players, so that's what we expect," he told MUTV.
"Going back to the game against Newcastle, we know that was nowhere near good enough and that's still stinging us.
"We can't have them anomalies where we go somewhere and we don't play as well as what we can, and maybe not show as much fight as what we could as well.
"This is a building block and something that we can take step by step without getting too carried away."