Arteta said afterwards: "We're obviously very disappointed with the result, especially with the way we have been performing. The first half was one of the best halves we have played this season against a top team. We should've scored three, four, five, we haven't scored. In the second half, the game changes, we struggle to gain momentum, we struggle to get the ball into certain areas and we were very sloppy with the ball and the game was there with not much happening. A few corners for them and then we concede a very poor goal and then, on top of that, we were chasing it and then we concede another one and it was a painful loss.
"I think we played much better than we did against Brighton in the first half. Much better. I think we should've scored three, four, five goals in the first half and that would've been a very different game. That's not the case and we have to accept that and we have to praise the opponent, they beat us and we have to move. It is about reacting now.
"For sure, because we had the momentum and we were the better team on the pitch but you have to play for 96/98 minutes and we haven't managed to maintain that level in the second half and that is down to us and we have to improve.
Asked if Arsenal have to win every game now, Arteta added: "We all know that, the impact is now. How you react to that, there was always going to be a bump in the road. We won 10, drew one. Unbelievable, everybody is on board. Win, win, win win, win, win, win, win - everybody is happy. Very easy to maintain momentum and be on top of that. It is now after that defeat, how you show you character and your leadership and going to Munich, we have a beautiful opportunity to do that."