Bacary Sagna felt Arsenal played at their full potential in the first half against AC Milan.
Sagna admitted the team's performance in the opening period was the best he has seen.
The right-back said: "I honestly can't remember us playing that well in a first half before. We played without any pressure. We had nothing to lose.
"We could only score goals but it was not enough.
"It is disappointing to go out but it will give us some momentum going in to the game against Newcastle on Monday."