"Obviously it's so important for me to repay the manager whenever he puts trust in me in these games," McTominay said after playing the full 90 minutes against Sevilla on Wednesday.
It was only a second Champions League start for the 21-year-old, who put in a mature display by pressing effectively and being efficient with his passing.
"And I thought the whole team tonight put in a real shift for the manager and I think going back to Old Trafford we're in a good position," he added. "I wouldn't say the best position because we didn't win, but we're in a good position because we can go back and fight for every ball and hopefully we can progress to the quarter-finals.
"It's all to play for. At 0-0, anything can happen. We're confident against any team we play. Hopefully we go back to Old Trafford and we can go through there."