Diego Lopez's mistakes emerging as another problem for AC Milan

Milan goalkeeper Diego Lopez has yet to keep a clean sheet this season in Serie A. Valerio Pennicino/Getty Images

When Diego Lopez joined AC Milan in August 2014, his signing was heralded as a great move by the club. The Spaniard was expected to add security between the posts and give the Rossoneri a solid base on which to build.

The 33-year-old went on to impress for the most part last season, aside from the occasional mistake, and offered guarantees and experience in a crucial position. However, so far this season, the number of mistakes is increasing and question marks are beginning to emerge over the former Real Madrid star.

Milan have had a difficult start to the season in general, and the atmosphere around the club has certainly deteriorated in recent weeks following some poor results. However, Lopez's decline is particularly worrying. Given the nature of his position and that with each error comes more scrutiny than any other player, he must overcome a difficult period in his career in Italy.

The media have picked up on his costly displays, most recently when he allowed Torino star Daniele Baselli to beat him at his near post, which in turn earned the Granata a share of the spoils in a 1-1 draw last Saturday.

Prior to that, Lopez could arguably have done better to deny Lorenzo Insigne in the 4-0 defeat to Napoli. In addition, his inability or perhaps apprehension in kicking long put Mattia De Sciglio under pressure against Empoli, and the visitors made the most of the situation to score and pile the pressure back on Milan.

The uncertainty is increasing and the mistakes are happening with greater regularity, and that in turn is risky as it threatens to impact the level of faith Lopez's teammates have in him. Essentially, Lopez never entirely convinces as there is always a feeling of a mistake around the corner. His shot-stopping ability is unquestionable, but he lacks presence and agility, which makes him a liability.

Milan have conceded 14 goals so far this season, which is the second-worst record in Serie A with only Carpi conceding more. Given their current situation, the last thing that coach Sinisa Mihajlovic needs is being unable to rely on a key player; whether or not Mihajlovic makes a change remains to be seen. In an ideal world, Lopez becomes the reliable presence that he was last year, making key saves such as that against Mauro Icardi in the Derby della Madonnina not so long ago.

Coupled with the fact that his potential replacements are risks in themselves, it presents a difficult decision for Mihajlovic. Christian Abbiati hasn't featured in so long that it would be a gamble to thrust him back into action, despite all the experience that he can draw upon.

Perhaps the more likely scenario is that 16-year-old Gianluigi Donnarumma gets his first start for the club if he can impress in the Trofeo Berlusconi against Inter on Wednesday night. Despite his young age, Donnarumma has risen through the ranks at Milan quickly and received his first senior call-up last season under Filippo Inzaghi. More recently, he saved a Toni Kroos penalty during a summer friendly against Real Madrid, and has been tipped for a big future with the Rossoneri given the talent that he has already displayed.

While that would seem like the sentimental choice, if he does start against Sassuolo on Sunday, are Milan and Mihajlovic risking breaking the confidence of a teenager before he can even get a foothold in the senior squad?

Admittedly, all these issues in recent weeks aren't just about Lopez, despite the fact that he is contributing to the problem. The defence, and Milan as a whole have yet to fully integrate and buy into Mihajlovic's methods. Perhaps if they did, it would make Milan a harder unit to break down.

Ultimately, the Serbian tactician has a big call to make. Either he sticks with Lopez,who will hope he can turn his form around and prove he can be a cornerstone of this team, or he pushes Donnarumma into the limelight and takes a huge risk. Whichever it is, Milan need to start to finding a way to tighten up in defence.