Arsenal defender Per Mertesacker says they only have themselves to blame for defeat at Swansea City.
The Gunners blew a 1-0 lead to lose 2-1 last night.
"The game was completely in our hands, especially in the second half when we scored," Mertesacker said. "Then we have to play serious football and not lose the ball but they got us on the break, and that's completely unbelievable in our situation.
"We have to play simple, even if we are 1-0 up - even more then. We played through the middle but we need to keep possession and keep patient, something that we did all the way through until the 60th minute and we had the game in our hands completely. That's what I mean by serious football.
"When you get such a result [like against Anderlecht] normally you come back quickly and after such a setback normally we bounce back immediately. Today that was not the game and we have to take the break now really seriously and work hard on the issues."
