Pablo Mari's Strong Debut Showed Arsenal's Need for a Competent Left-Footed Centre-Back

​Arriving to little fanfare - he was spotted in a Brazilian airport with more people crowded around the vending machine than vying for his autograph - the gamble taken on Pablo Mari was one that garnered the obligatory doses of disillusion.

A late-bloomer who never really shone in European football was supposed to walk through the Emirates Stadium doors and be the saviour to Arsenal's unsalvageable defensive shambles? Oh, and he was nowhere near match fit having not played since late December? Right, sure. Wait, and he cost a £4m loan fee? Christ. And don't get me started on Cedric Soares.

So when Mari finally made his Gunners bow during the 2-0 FA Cup fifth round victory over Portsmouth, fans were given a brief taster of the Spaniard's capabilities and the ideas Mikel Arteta has in store for the future.

A left-sided centre-back who is left footed is paramount to that.

Since Arteta has taken the reins, he's been forced to play ​David Luiz - a right footer - on the left-hand side of central defence. His performances have improved over the last few months, but his distribution is not as assured on that side and precious time is wasted during build up play when he is constantly shifting the ball to his right side.

Arteta hasn't had a choice, though. He inherited a squad boasting six right-footed centre-backs, none of whom were, let's say, any good. 

Which is why Mari's strong showing at Fratton Park bodes well. What does it bode well for? A number of things, really.

It will get the best out of Luiz, that's for sure. Granted, I know, Luiz's 'best' is hardly inspiring, but tough luck, he's the best ​Arsenal have got for the rest of the season at least.

As seen against Pompey, the addition of a defender comfortable on his left foot meant Arsenal could switch to a back three when in possession. This is a ploy Arteta looks to have began implementing to make up for Bukayo Saka's defensive deficiencies, and one that initially started being performed by Granit Xhaka.

However, ​Xhaka is slow. Mari isn't the quickest, but he's at least not on the Swiss' level.

His overall showing was solid, which is encouraging, but he's unlikely to be a long-term star for the club moving forward. There is every chance they'll make the move permanent if he maintains such performances, but he's hardly the calibre of centre-back that is going to see Arsenal challenge for the ​Premier League top four again.

But it's given Arteta the platform from which to instil new ideas and, for the most part, they came off against the League One outfit. No disrespect to Portsmouth, who put in an impressive first half display in particular, but tougher challenges will face Arsenal before the end of the season. Most notably in the top flight, but equally in the FA Cup quarter-finals.

Saka has been a revelation for the Gunners this season, and with Sead Kolasinac out injured and Kieran Tierney only just returning to full training, Mari could be a crucial component in drawing the most out of the academy product. 

He was confident, vocal, positioned himself well and looked strong in the tackle. There may be a certain caveat to that given the quality of opposition, but as far as debuts go, it wasn't all too disheartening.

Mari has shown he can be a solid stop-gap until the summer comes around. Defensive reinforcements are an absolute essential, even with William Saliba's hotly-anticipated - and desperately needed - arrival. 

With every game deemed a cup final between now and the end of the season, not only will the 26-year-old Mari potentially play a crucial role, but he could help set the foundations for the way Arteta ultimately wants his team to play.

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