Mannone was in goal for Saturday's 2-1 defeat against Manchester United and hopes the side will quickly learn from the mistakes made at Old Trafford.
"I think we need to really focus on ourselves now and be ready because Tuesday is another game like this one," he told Arsenal Player. "It's not good when you start like [we did at Old Trafford].
"We know that if you go 1-0 down, it's difficult because they defend really well. They put bodies behind the ball and it's difficult to break them down, especially if you don't increase the pace of the passing.
"We passed it well but we don't do it enough to create chances. I think we only had two or three shots in the last five minutes. Obviously you can't win the game like that.
"We just need to be focus and stick together because now is the time to react at a big club like Arsenal."