Arsenal's inability to hunt down Leicester in the Premier League title race is down to a lack of discipline, according to Per Mertesacker.
While their north London rivals Tottenham have stayed on the heels of leaders Leicester, Arsene Wenger's men have fallen off the pace. They are 13 points behind the Foxes with five games left and even face a fight to stay in the top four.
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Four months ago Arsenal topped the table. Mertesacker said: "It's about discipline. We lacked that desperation to defend and get everyone behind the ball.
To come back to that level is absolutely important in the Premier League, and if you don't you will get punished. These details are very important to us and everyone can see it."
Wenger's men next face West Brom on Thursday night and will be desperate to reignite their Premier League campaign with fifth-placed Manchester United breathing down their necks.
Jens Lehmann, the goalkeeper in the last Arsenal team to top the table in 2003-04, has revealed his concern over the recent efforts of his former club.
"It's a little bit more disappointing than before because everybody thought Leicester could be caught at the end of the season," said Lehmann, speaking at the Laureus Sports Awards in Berlin.
"They could, but unfortunately only by Spurs and not by Arsenal. If you're an Arsenal supporter there have been better times.
"Have they thrown it away? Yes, it's a fact, of course they did. The table now is different."