Back in mid-January, it seemed like Arsenal had turned the ­corner when it defeated Manchester City on their own ground 2-0. A tactically sound and disciplined Gunners side finally got an outstanding victory over a fellow top-four team.

But since then, Arsenal have reverted to their old ways that culminated in a shocking 3-1 defeat at home last week in the Champions League.

Their conquerors in the ­second-round first leg were not Real Madrid or Bayern Munich, but Monaco, currently fourth in the French league.

It is not completely over, as Arsenal can still advance but only if they score at least three goals in the second leg. In other words, Arsenal might as well prepare to bow out of the Champions League at the same stage as in the last four editions.

There were already warning signs from a month ago after the defeat to rivals Spurs on February 7. Narrow wins over teams like Leicester and Crystal Palace followed in which Arsenal struck early but then struggled to preserve leads.

Manager Arsene Wenger must take blame for failing to maintain the defensive-minded approach from the City win. Apparently Wenger deemed the rigid defensive approach appropriate only for one game. The Monaco defeat saw the same defensive lapses and midfield frailty that characterized several Arsenal losses this season.

One of the biggest issues is midfield, specifically German star Mesut Ozil. Against ­Monaco, he was hardly present and it was not the first time he has had poor performances in big games. Ozil was on the bench against Manchester City but since then, he has started regularly alongside Santi ­Cazorla. Both are good offensive players, but weak defensively, and this causes a serious deficiency in midfield. The Monaco defeat exposed this weakness and Wenger should consider dropping Ozil, given both his defensive shortcomings and Cazorla's better form.

Alexis Sanchez has not scored much recently, partly due to coming back from ­injury but also possibly because of ­exhaustion. Wenger should have rested him more in December and January, as it was apparent that Sanchez was driving himself into the ground.

Victory over Everton Sunday was good though not too convincing. Next week, Arsenal will meet Manchester United in an FA Cup quarterfinal. ­Arsenal will do well to ensure no ­repeat of the Champions League ­debacle against Monaco.

The author is an editor with the Global Times. hiltonyip@globaltimes.com.cn