Arsene Wenger must reinforce Arsenal if he is still manager next season

Building a football team requires a curious kind of alchemy. After a winter of dysfunction, Arsene Wenger has returned to the laboratory, where he'll try and come up with a formula that can work for Arsenal. On the evidence of their last game, a convincing 2-0 win over Everton, he might have discovered a blueprint for success. Should he remain at the helm beyond the end of the season, he must tailor his transfer activity according to this new setup.

Arsenal's struggles at inopportune times this season have made a mockery of Wenger's decision to enter the campaign without making a single outfield signing. If Wenger can resist the calls for him to abdicate and prolong his reign across another transfer window, he cannot afford to make the same mistake again.

The fact that he's had to rip his original plans up makes it clear that there is room for improvement. Over the past few weeks, there have been key changes right through the spine of the side. Per Mertesacker has been dropped at centre-back, Mohamed Elneny has been plunged into action in the middle of the park and Danny Welbeck has supplanted Olivier Giroud as the spearhead of the attack. Even Nigerian teenager Alex Iwobi has found himself propelled into the first-team picture. While those individuals have acquitted themselves well, Arsenal will surely be looking to improve on them when the window reopens.

Take the situation at centre-half. Mertesacker's demotion felt as if it had been, rather fittingly, somewhat slow in coming. The German's lack of pace has been an Achilles' heel throughout his career, and it was beginning to become Arsenal's. Uncharacteristically for him, he also made several high-profile mistakes in big games this season, with Gabriel Paulista the man who has profited in the short term. However, he's yet to produce the kind of performances to suggest he will occupy the spot alongside Laurent Koscielny beyond May. If Wenger has lost faith in Mertesacker, it's essential he moves for a top-class centre-back this summer.

In the centre of the park, Elneny has been an efficient and energetic performer. At Goodison Park, his performance alongside Francis Coquelin appeared to show the making of an effective partnership. If Elneny continues to improve at this rate, it's possible Wenger will allow him to continue in his box-to-box role. However, with the likes of Tomas Rosicky, Mikel Arteta and Mathieu Flamini all set to leave the club this summer, Arsenal will need to recruit at least one more central midfielder.

Wenger's priority should be a player who shares Elneny's disciplined approach to the role, but is perhaps a more gifted ballplayer. Alongside Coquelin's ball-winning skills, that could give the Gunners the ideal balance at the heart of their side.

Iwobi's emergence is as much to do with the deficiencies in Theo Walcott and Alex Oxlade-Chamberlain as the youngster's own talent. The England pair have both failed to cement a spot as the right-sided figure in of Arsenal's three-pronged attack, and Iwobi has subsequently jumped ahead in the queue. However, it's not an ideal situation that a 19-year-old is forced to play regularly for a side who supposedly have ambitions of challenging for Europe's major honours. An incisive, direct-running wide player will surely be on Wenger's shopping list come June.

Then we get to the attack. It feels as if Arsenal have been chasing a top-class striker since Robin van Persie's departure in 2012. This must surely be the year when Wenger pushes the boat out to get the centre-forward Arsenal need. Welbeck has done well through the middle since returning from his 10-month layoff, but he lacks the ruthlessness required at the elite level. Wenger should look for a player who can replicate Welbeck's mobile style but with the added benefit of composed finishing. Finding such a player won't be easy, but a tentative bid for Everton's Romelu Lukaku would not be a bad place to start.

All this might sound like fantasy football, but Arsenal have the resources to improve in all these areas. Wenger's recent changes to the side have prompted an upturn in performances, but they don't have to be long-term solutions. Arsenal can afford to improve upon their current options. If they're serious about winning the Premier League, they'll have to.