Arsenal boss Arsene Wenger admits he will be plagued by his team's midweek Champions League capitulation against AC Milan "until the last day of [his] life".
The Gunners were thumped 4-0 in the last-16, first leg tie at the San Siro after producing a woeful performance reminiscent of the 8-2 beating they took against Manchester United earlier in the season.
Wenger conceded afterwards that Arsenal's chances of progression in the competition had vanished - but he is now stressing that his players cannot afford to throw in the towel in the Premier League or FA Cup, in which they face Sunderland on Saturday.
"It never gets out of your system because you take it with you until the last day of your life," he said. "You can find 100 explanations why we had a poor performance and an off day. We lost against a good Milan team, not an exceptional one. Unfortunately we were punished severely.
"It is important not to dwell on that too much, instead focus on the next performance, respond in a positive way and ensure we have the mental qualities to be at this club. We have put together a good series of results and we can consider that night was just an off day. We are focused on what we have done well recently because we go into a battle now where we need confidence, belief and great commitment.
"We are in fourth position in the Premier League and we have an opportunity to qualify for the quarter-finals of the FA Cup. It is important that we are up for that and do not feel sorry for ourselves. Not only is the FA Cup at stake, but so is the response and the mental attitude of our team as well. I'm convinced that we will produce the response we need."