Laurent Koscielny has admitted that Arsenal failed to follow Arsene Wenger's gameplan early on during their Europa League quarter-final second leg at CSKA Moscow.
The Gunners led 4-1 from the first leg at the Emirates Stadium but found themselves trailing in Russia to goals from Fedor Chalov and Kirill Nababkin.
Arsenal sat deep and invited pressure onto themselves during much of the game, which was ultimately salvaged as Danny Welbeck and Aaron Ramsey struck for a 6-3 aggregate win.
"It was not the plan [to defend deep]," Koscielny told BT Sport after the game.
"I think we missed a lot of movement, to be available for our teammates. We didn't win duels. They played well, had opportunities and took them. It put pressure on us, if they score we are out.
"So I am happy because we came back, but our performance was not enough for the stage of the competition. We will see the draw, but need more confidence in our game."
Arsenal are joined by Atletico Madrid, Marseille and Red Bull Salzburg in the last four of the competition, with the draw taking place on Friday at 12pm.
