Arteta said: "The game had different moments. We started really well, we were dominant, didn't concede anything. We scored a really good goal and after that is the moment of the game when Ben (White) is in front of (Manuel) Neuer and if it was 2-0 it would have been a very different game.
"They scored and it created some uncertainty, the second goal was unusual for us to concede but it is the Champions League, you make a mistake and get punished.
"We allowed them the spaces to run and they were very dangerous but even at 2-1 we tried to make a rhythm, we were composed and didn't try to rush things and the changes had an impact on the game.
"In the Champions League you give something they will take it. You get punished. That is part of football as well.
"The things we can control is do the simple things better."