Arsenal midfielder Santi Cazorla has admitted that there is a growing sense of frustration over the club's poor run of form.
The Gunners dropped to 10th in the Premier League yesterday after losing 2-0 at home to Swansea City.
Cazorla believes that Arsenal are struggling to control matches and also conceded that his side have fallen behind their title rivals in terms of quality.
He said: "We don't know exactly what the problem is, it's true that we're inconsistent.
"I believe that to challenge for the Premier League, those games can't get away from us. Take the Fulham game, we were 2-0 up. You can't then be drawing within five minutes, those points aren't coming back. And the other day against Aston Villa, there's a game which I believe we really had the desire to win, because these are points that we can't let get away.
"It's a little bit frustrating. We're a good team with good players, training well. But there are moments in those games when we don't know how to control them. There's a significant gap between us and United and City. They've got away a bit. We have very little margin for error."
Defeat at the hands of Swansea condemned Arsenal to their worst ever start to a league season under Arsene Wenger.
