AC Milan vs. Barcelona: Prediction, Preview and Key Players at the San Siro

On Tuesday night, AC Milan take on Barcelona in the UEFA Champions League once more in what is the two clubs' seventh meeting in the competition since 2011.

In their last meeting at the San Siro in the last 16 of last year's tournament, Massimiliano Allegri's Milan emerged with a shocking 2-0 victory. 

While Barcelona added Brazilian superstar Neymar to their squad this summer, Milan will be without forward Stephan El Shaarawy, per Football Italia, as well as goalkeeper Christian Abbiati and Mario Balotelli, per Goal.com.

With just three wins from their opening eight games of the Serie A season, it is fair to say expectations are not high regarding Milan's chances at the San Siro.

Victory over Celtic and a draw with Ajax have seen the Italians start their 2013-14 Champions League in good shape, while Barcelona have begun with consecutive victories in the competition.

For Milan, the next two games will carry low expectations, but any point gained will prove crucial to their hopes of progression from the Group Stage.

The Associated Press reports, via the Globe and Mail, that both Lionel Messi and Carles Puyol will be fit for the Catalan side, so the task ahead for Allegri's team looks formidable.

Key Players

Alessandro Matri

Barcelona are far from the tallest side in this year's competition, so set-piece delivery into the box is one way Milan can look to expose the Catalan side.

In Alessandro Matri, they have a striker who, while not especially tall, is strong in the air and will be the main focal point of the attack in the absence of Balotelli.

Sadly for Milan, Matri has thus far drawn a blank in front of goal this season. However, with few alternatives to lead the line, he will continue to be given opportunities to change that record.

If he can find form Tuesday night and help down Barcelona, his slow start to the campaign will be immediately forgotten.

Neymar

Brazilian superstar Neymar has slotted in perfectly since joining Barcelona earlier this summer, scoring two league goals and providing five assists in his opening seven league games for the Blaugrana.

He tormented Celtic last time out in the Champions League and will hope for a strong showing on this occasion to put the controversies of his alleged simulation in that game well and truly behind him.

The former Santos man will come up against pacy right-back Ignazio Abate on this occasion, a man he has opposed one-on-one at the international level before. While Abate is not the best defender, he is very quick and will not be simply beaten for pace as Neymar so often does to others.

With Messi likely to be eased back into action, Neymar will once more be the man Barca turn to for inspiration. If he can come good, it will be a long night for Abate and his colleagues.

Kevin Constant

The fact that converted midfielder Kevin Constant is currently first-choice left-back in the continued injury absence of Mattia De Sciglio is a worrying indictment of the falling standards of the Rossoneri in recent years.

Constant is not a great defender by anyone's measure, ranking among the worst in Milan's squad for fouls conceded and occasions dribbled past by an opposition player, per WhoScored. Given the speed and width to Barcelona's attacking under Martino, he will have to be on top of his game.

Unfortunately for the Guinea international, he will likely be directly up against either Pedro or Alexis Sanchez on the night. Containing either player will not be an easy task.

The game will represent a major test of his abilities to succeed as a left-back in high-level competition.

Cesc Fabregas

Should Messi be eased back via the substitutes' bench, as would be expected, then Cesc Fabregas is likely to reprise his role as the central attacking player for Barca once more at the San Siro.

The former Arsenal player has been brilliant as a No. 10 this campaign, topping the La Liga assist charts with six contributions. However, his effectiveness as a creative force has been limited when used further forward.

Cesc is at his best with play occurring ahead of him, whereas he is too often required to play with his back to goal when featuring as a false nine. That is not to say, however, that he is not a more than useful alternative in the role.

He has been key to Barcelona's attacking play this season, contributing more than either Xavi or Andres Iniesta to his side's cause, and he will hope to exploit any weakness in a Milan backline that has conceded 13 times in eight league games come Tuesday night.

Prediction: AC Milan 1-3 Barcelona