The two teams played out a 1-1 draw in the first leg last week, and Moyes claims that he may take on a more offensive approach for the second.
"You can go into some Champions League games from recent times when teams sat back and waited and waited and waited and then got something from the game and got through. I don't think there is any shame in what we did [in the first leg], not by a long way," he told reporters. "Tactically, I thought we played very well on the night. But I have got to say, in the second game, we might need to think differently, look at it in a different way to the first game.
"Tactics is something that I am looking at and thinking about. We played with a game-plan and I would think Pep (Guardiola) would need to alter his team slightly. Tactically, they will play the same type of game, maybe differently in terms of positions. For us, we have to make a decision, do we play differently? That is something I am mulling over at the minute.
"I think the way modern football is going, you just never know [what can happen in games]. Many teams have lots of possession but your job is to score goals at the end of the day. Many teams who play on the counterattack might get a goal."
The second leg takes place at the Allianz Arena on Wednesday evening.