Sokratis Papastathopoulos has warned Arsenal's rivals they are confident of cracking the top four having reached just "70 to 80 per cent" of their potential under Unai Emery.
Sunday's hard-earned 2-1 win at Bournemouth extended the Gunners' unbeaten streak to 17 matches in all competitions.
Emery's men have already equalled the four Premier League away victories they secured last season and are now just one point adrift of the Champions League places.
A switch to a three-man defence at the Vitality Stadium suggested Emery is still experimenting with formulas to unlock his team's top form.
"We are around 70 to 80 per cent [of our potential]," Greece defender Sokratis told reporters.
"Of course we need to improve, of course we would like to put Arsenal in the top teams in the Premier League. We try every day for this.
"We need to improve sometimes to not lose the ball, or when we have the ball to finish the action and score.
"That is the difference, we need to improve and we know this. We work every day and I am happy I am part of a team that work very good together."
Emery's men have the chance to draw level with third-placed Tottenham on 30 points when they host the north London derby at The Emirates Stadium on Sunday.
But Sokratis rejected the notion the match could make or break Arsenal's hopes of permanently settling in the top four.
"Of course it will be a very important game but I don't think it is a game that can give you the Champions League," he said.
"For example, if we win against Tottenham and lose other games, it is the same thing. It is very important that in every game we go for the win.
"We have confidence [that we can break into the top four] but it is not easy, we know that."