Per Mertesacker believes Arsenal’s Champions League collapse should act as a wake-up call.

Arsene Wenger’s side blew a three-goal lead to draw 3-3 against Anderlecht and missed the chance to secure qualification to the knockout phase.

An angry Wenger accused his players of being complacent and captain Mikel Arteta was furious with the team for “throwing everything away”.

Mertesacker was also scathing about the defensive collapse and believes it should serve as a warning to Arsenal that they need to improve.

“That was a good warning last night that everyone should raise their game and give maybe 10 per cent more when it is needed,” said the German, who has called for an immediate response when Arsenal face Swansea in the Premier League on Sunday.

Former Arsenal forward Paul Merson described Wenger as “tactically clueless” and Mertesacker admits Arsenal did not defend as a team.

“When we drop sometimes everyone has to be involved to defend,” he said. “You can’t afford for just five or six players to defend, or just the back four. That is what we lacked especially in the final third and in the last 20 minutes.

Arsenal v Anderlecht: Player Ratings 12 show all Arsenal v Anderlecht: Player Ratings 1/12 Woijech Szczesny: 6 On his return from Champions League suspension Szczesny had to be alert early on to keep the visitors out but to be fair to him there wasn’t a great deal he could do about any of their three late goals. GETTY 2/12 Calum Chambers: 6 A quiet game for Chambers this evening – didn’t make any huge personal errors during the Anderlecht comeback but didn’t stamp his authority on the game either. Getty 3/12 Per Mertesacker: 5 Faced with the unenviable task of playing alongside Monreal, Mertesacker unsurprisingly looks rather unstable at the moment - will be disappointed he was beaten in the air for the equalising goal. Getty 4/12 Nacho Monreal: 3 In fairness to the Spaniard, he’s playing out of position - but that doesn’t change the fact he looks absolutely horrendous – surely there has to be someone else who can do a better job than him - isn’t Steve Bould still around? Getty 5/12 Kieran Gibbs: 7 Once Laurent Koscielny returns, Monreal should not get a place back in the Arsenal side because this young Englishman is in fine form. Solid defensively and a real asset going forward – he should be ahead of Luke Shaw in the England pecking order. Getty 6/12 Mikel Arteta: 6 Took his penalty calmly and passed the ball well but doesn’t offer his defence the sort of protection required from his position at the top level. Getty 7/12 Alex Oxlade-Chamberlain: 8 With his injury woes appearing to be behind him, the 21-year-old is putting together a fine run of form – his goal and general play tonight showed why he must start on a regular basis. Getty 8/12 Aaron Ramsey: 6 Not quite back to his best following injury but had some nice moments as Arsenal dominated the middle part of the game. Getty 9/12 Alexis Sanchez: 8 Looks a better signing with every passing game – wonderful technical ability combined with terrier-like enthusiasm makes the Chilean near unplayable at times – he scored a stunning volley to give Arsenal a 2-0 lead. Getty 10/12 Santi Cazorla: 6 Can’t help but feel he’s at the bottom of the pecking order when it comes to Arsenal’s riches in attacking midfield – not bad but not as impressive as his rivals for his place in the side. Getty 11/12 Danny Welbeck: 7 The goals have dried up a little for Welbeck but he is doing a fine job for the team and showed his worth as he won a penalty this evening. Getty 12/12 Mathieu Flamini: 5 Brought on for Arteta with half-an-hour to go and Arsenal cruising to victory, it would be hard to argue he had a positive impact. Not the answer to the Gunners’ weakness at the base of their midfield. Getty 1/12 Woijech Szczesny: 6 On his return from Champions League suspension Szczesny had to be alert early on to keep the visitors out but to be fair to him there wasn’t a great deal he could do about any of their three late goals. GETTY 2/12 Calum Chambers: 6 A quiet game for Chambers this evening – didn’t make any huge personal errors during the Anderlecht comeback but didn’t stamp his authority on the game either. Getty 3/12 Per Mertesacker: 5 Faced with the unenviable task of playing alongside Monreal, Mertesacker unsurprisingly looks rather unstable at the moment - will be disappointed he was beaten in the air for the equalising goal. Getty 4/12 Nacho Monreal: 3 In fairness to the Spaniard, he’s playing out of position - but that doesn’t change the fact he looks absolutely horrendous – surely there has to be someone else who can do a better job than him - isn’t Steve Bould still around? Getty 5/12 Kieran Gibbs: 7 Once Laurent Koscielny returns, Monreal should not get a place back in the Arsenal side because this young Englishman is in fine form. Solid defensively and a real asset going forward – he should be ahead of Luke Shaw in the England pecking order. Getty 6/12 Mikel Arteta: 6 Took his penalty calmly and passed the ball well but doesn’t offer his defence the sort of protection required from his position at the top level. Getty 7/12 Alex Oxlade-Chamberlain: 8 With his injury woes appearing to be behind him, the 21-year-old is putting together a fine run of form – his goal and general play tonight showed why he must start on a regular basis. Getty 8/12 Aaron Ramsey: 6 Not quite back to his best following injury but had some nice moments as Arsenal dominated the middle part of the game. Getty 9/12 Alexis Sanchez: 8 Looks a better signing with every passing game – wonderful technical ability combined with terrier-like enthusiasm makes the Chilean near unplayable at times – he scored a stunning volley to give Arsenal a 2-0 lead. Getty 10/12 Santi Cazorla: 6 Can’t help but feel he’s at the bottom of the pecking order when it comes to Arsenal’s riches in attacking midfield – not bad but not as impressive as his rivals for his place in the side. Getty 11/12 Danny Welbeck: 7 The goals have dried up a little for Welbeck but he is doing a fine job for the team and showed his worth as he won a penalty this evening. Getty 12/12 Mathieu Flamini: 5 Brought on for Arteta with half-an-hour to go and Arsenal cruising to victory, it would be hard to argue he had a positive impact. Not the answer to the Gunners’ weakness at the base of their midfield. Getty

“We have to defend better as a team. We did not stop them (Anderlecht) playing and they are good at it. As you could see, even in the final third, when you do not put them under pressure, they can deliver good balls through the middle. They can cause trouble and we just left them playing. So in general that was the problem.”

Arsenal were booed off at the final whistle and Wenger conceded it was “impossible” to qualify for the last 16 as group winners. The Gunners, who are five points behind Group D leaders Borussia Dortmund with two games remaining, are now set for a difficult draw against one of Europe’s most fancied teams in the next round.

“Last night is a small setback for us but it is a good warning and we will bounce back quickly,” said Mertesacker. “We are really good at that, we have shown that a couple of times. We still have a comfortable situation in terms of going through. We want to secure second place and we still have a big advantage after four games.”

Arteta did not hold back in his assessment of how Arsenal failed to close out the win.

“It is just not good enough,” said the midfielder. “We have thrown everything away. Even after conceding the first goal we still had a two-goal lead.

“It has blown our chances of winning the group and that is the main aim at the start of the competition. We need to analyse the mistakes and what happened in the second half, because it is not at the level required at this club.

“We have another two chances still, but you can’t miss your chances in the Champions League, because every team has qualities and you can see what happened.”