The Gunners thumped six past newly-promoted Southampton in their last domestic outing on Saturday, but geared up for the trip to the Etihad with a narrow 2-1 victory over Montpellier in their opening Champions League group game.
Nevertheless, speaking after their win at Stade de la Mosson, the captain believes Arsenal can triumph over the Premier League champions if they play their own game.
"If we stay focused, confident and play our own game then we can get a result [against City]," Vermaelen told Sky Sports.
"We have to keep on playing like we are. The second half was not great [against Montpellier] but we had some good performances like, for example, on Saturday."
Focusing on Tuesday night's game, Vermaelen recognised that his side rode their luck on occasion in the second half, but was happy with the performance before the break which saw the Gunners go behind to a Younes Belhanda penalty - which the centre-back gave away - before two goals in as many first-half minutes turned the tie around.
"In the second half we were not great," he continued. "In these kind of situations [a narrow lead] you have to stay calm and make sure you don't concede a goal, which we did but the team performance was not great.
"I didn't think it was a penalty, maybe I'll have to see [the replays] back. Maybe I should not have gone for the challenge but I was 100 per cent sure I could win the ball."
Lukas Podolski, who levelled the tie before Gervinho's winner, echoed his captain's comments but highlighted the importance to get points on the board early on during the rigorous Champions League group stage.
He added: "We were very good in the first half, but not so good in the second. But we have the three points, which is important in the Champions League and we can now look forward to the game against Manchester City [on Sunday]."