Arsenal manager Arsene Wenger believes Champions League qualification is still a possibility this season, though he admitted it would be a challenge.
Following the Gunners' loss to north London rivals Tottenham on Sunday, Wenger's side now trail the top four by five points and could miss out on Europe's elite competition for the first time in the Frenchman's 16-year reign.
Wenger, though, said his team would not be giving in.
"It will be a massive challenge, I said before the game that we could not afford to drop points," he told reporters after the match. "However, I still think it is possible and we will fight for it, that is for sure."
Arsenal trailed 2-0 at half-time following almost identical goals from Gareth Bale and Aaron Lennon, and Wenger was annoyed by his defence's lapses in concentration.
He said: "It is frustrating because we put so much effort in and lost the game when we were on top, we were 2-0 down when we should have been 2-0 up.
"It is difficult to understand how you lose a game like that.
"We had a great attitude and came out with no points because we were not efficient where it matters, at the front and in the back.
"Also, without being at any moment dominated, the only times Tottenham were dangerous was on counter-attacks. If you are dominated and they create chance after chance, okay you accept it, but this was a strange game to lose."
Despite Per Mertesacker's headed goal early into the second half, Arsenal could not capitalise on their dominance and failed to come away with any points from White Hart Lane. Wenger was perplexed as to why his side can play well but end up on the wrong side of the result.
"It happened to us many times this season and only in big games," he added. "It's difficult to say why, there's no common thing, in all the games there is a different problem.
"I cannot fault the attitude or the effort that the team produced, or the spirit the team has shown, but you give yourself a mountain to climb every time in a game of that magnitude."
The Gunners now move on to the second leg of their Champions League tie with Bayern Munich next Wednesday. Arsenal go to the Allianz Arena needing to overturn the 3-1 defeat suffered at the Emirates Stadium.