Arsenal’s Champions League campaign got off to a miserable start after they were convincingly beaten by an excellent Borussia Dortmund side at the Signal Iduna Park. The Gunners were thoroughly outplayed by Jurgen Klopp’s side and but for the profligacy of Henrikh Mkhitaryan, the score-line would have been much more comprehensive.

Tuesday night’s defeat felt like ground-hog day for Arsenal and their fans. Last season, for all their progression, their failure to compete against the division’s top sides cost them in their title-bid.

Against last season’s top three away from home, Arsenal conceded an incredible 17 goals. They were destroyed with consummate ease; their defensive naivety and susceptibility to the counter-attack a hallmark of their shortcomings.

The disappointing defeat was a damning indictment of the progression still required to take Arsenal from serial pretenders to genuine contenders. Arsenal’s fantastic costless-flowing football can overwhelm lesser opposition, but it’s against the elite where they must acknowledge the opposition’s strengths and adapt in an attempt to negate their threat.

Arsène Wenger’s biggest issue is the defensive-midfield position. The Gunners are desperately crying out for a midfield enforcer, who has the discipline to break up the play and sit and protect their back-four.

In a recent interview with French television station beIN Sport, the veteran Arsenal boss acknowledged the need for a defensive midfielder. Wenger said: “I'm happy with our signings, but we still need a physical presence with prodigious ability like Vieira or Petit.”

It was a startling admission from the Frenchman, particularly just days after the transfer window slammed shut. Arsenal were heavily linked with a move for the combative Portuguese William Carvalho, but the deal collapsed on deadline day; leaving Arsenal with the ageing duo of Mikel Arteta and Mathieu Flamini as their senior players in the role.

Arteta, appointed as skipper earlier this summer due to Thomas Vermaelen’s departure, had an extremely poor evening in the Arsenal midfield, although his limitations were brutally exposed and exacerbated by the 4-1-4-1 formation deployed by Wenger at the beginning of the season.

Thus far, the Gunners have struggled to adapt to this change of tactical approach. There is a distinct lack of cohesion throughout the side. Arsenal’s midfield are playing too far forward, leaving acres of space in front of the defence when oppositions’ counter.

The high-line used by Arsenal clearly exposed Arteta’s lack of pace, as the likes of Mkhitaryan, Aubameyang and Immobile had costless-reign to run at the Arsenal back-line. Although the additions of Danny Welbeck and Alexis Sanchez have enabled the North Londoners’ to press defences higher up the pitch, Arteta lacks the mobility to reciprocate this.

Per Mertesacker has also really struggled with the change in system. The imposing German bases his game on positioning and discipline; he reads the game and spots danger superbly. Nevertheless, he lacks any semblance of pace. Therefore, with Aubameyang and Immobile running at the Arsenal defence, the World-Cup winner was left stranded on numerous occasions.

The new formation has also encouraged the Arsenal full-backs to play further forward, almost playing as wing-backs. Kieran Gibbs and debutant Hector Bellerin both performed reasonably well, although for Dortmund’s second goal, they were both caught too far up the pitch.

Both of Dortmund’s goals came courtesy of clinical counter-attacks. The first goal came from Arsenal losing possession from a regulation-throw in, leaving the entire midfield caught up field; Immobile glided through the defence, before firing a low angled shot past Wojciech Szczesny.

Just moments into the second period, a simple ball was played over Arsenal’s high-defensive line into Aubameyang’s path and a misjudgement from Szczesny allowed the talented forward to round him and slot the ball into the vacated net.

Both goals were completely avoidable. Admittedly, Arsenal were uncharacteristically wasteful in possession, but if they had sat a little deeper, Dortmund’s counter-attacking threat would have been negated. The susceptibility to the counter-attack was so painfully reminiscent of the humbling defeats against Liverpool and Chelsea last term.

Arsène Wenger’s team selection was also questionable. Mesut Ozil's quality cannot be questioned, however he’s been a periphery figure this season, especially when played on the left-wing.

With the current formation, Aaron Ramsey, Jack Wilshere and Ozil cannot all play in the central midfield role, but Wenger is trying to accommodate Ozil by playing him on the wing, which has largely nullified the enigmatic German’s threat. In addition, he is not renowned for his work-rate, which also exposes his full-back on the overlap.

Ozil is one of the world’s best in the number 10 role, but Arsenal have a plethora of options there. However, with the gruelling fixture list ahead, there will be plenty of opportunities to rotate the squad.

The energy and work-rate of Alex-Oxlade Chamberlain could have been beneficial against a side of Dortmund’s intensity. Chamberlain would have posed a greater and more direct threat on the counter-attack, whilst he is certainly more industrious than the former Real Madrid man.

Every time an Arsenal player lost possession, there seemed to be at least four or five players caught up the pitch. Against a team with Dortmund’s counter-attacking ability, you must be more intelligent and tactile, particularly away from home.

Despite the tactical faults and question marks over team selection, you simply cannot compete against a team of Dortmund’s quality with so many poor individual displays.

Alexis Sanchez, one of Arsenal’s best players this season, was a frustrated figure after being caught in possession too often due to Dortmund’s relentless pressing. Ozil was anonymous; Mertesacker was lacklustre; Arteta was extremely poor, whilst Ramsey, who has struggled with his new role in the side, was way below-par.

All is certainly not lost for Arsenal; Dortmund are comfortably the toughest test the Gunners will face in the group phase. There’s no shame in losing to Klopp’s exuberant side, but it’s the manner of the defeat that will concern Wenger.

However, prior to Tuesday night’s defeat, The FA Cup winners were unbeaten in fourteen matches, their longest unbeaten run since the 2008/2009 season, so perspective is vital. It was a very poor performance, but the key is that Arsenal bounce back and rectify these tactical issues.

Making mistakes is inevitable in competitive sport, but failing to rectify glaring issues is not. Arsenal and Wenger must address these failings and quickly, or face being outclassed on the big stages once more.