Arsenal manager Arsene Wenger feels his team's attacking intent left them exposed in the 3-2 defeat to Olympiakos.
The Gunners enjoyed just under 70% possession in the game and also had nine shots on goal, compared to Greek club's four, but couldn't avoid the defeat in the Champions League group stage.
"They have played together for six months. On the right, we had Alex Oxlade-Chamberlian, on the left Alexis (Sanchez) and up front Theo Walcott.
"That is the team that plays always. It is either Oxlade-Chamberlain and (Aaron) Ramsey or Cazorla and Ramsey. We were open because we attacked and went forward."