AC Milan vs. Arsenal: 7 Lessons Learned After Gunners Humiliation

How did it all go so wrong?

AC Milan came into this match riding high after their 2-1 win over title-rivals Udinese took them back to the top of the league. But Arsenal also came into this game on good form, beating a good Sunderland team 2-1 in their last game and humiliating Blackburn Rovers 7-1 in the game before.

How then did things go so badly for the Gunners, to the point where AC Milan's progression is practically guaranteed?

Let's look at the lessons learned from the game to find out.

Arsene Wenger Got His Tactics Wrong

Although Arsenal have played in a 4-3-3 for the majority of the season, Wenger decided to experiment a bit today, playing a 4-2-3-1 with Rosicky and Theo Walcott playing behind Robin van Persie. At halftime, he switched to a 4-4-2 with RVP and Thierry Henry leading the line.

Both tactics failed miserably, as Arsenal conceded twice in both halves.

It wasn't the formation that primarily contributed to Arsenal's downfall, but it did have an impact. Why did Wenger feel the need to change his formation? Did it have something to do with not wanting to win the ways Spurs did against AC Milan last year?

Whatever the reason, it was a mistake Wenger paid dearly for. One wonders, if Arsenal had gone with their 4-3-3 that has been so successful in previous weeks, would they have lost as badly? Would they have won?

I guess we won't know, at least not until Arsenal face off against AC Milan in the return leg.

Massimo Allegri Got His Tactics Spot on

Arsene Wenger may be known as "The Professor" to many, but today Allegri made him look very much like the student.

Against Arsenal, Allegri utilized a diamond midfield formation, with Ibrahimovic and Robinho upfront and AC Milan's usual flat-back four playing in defense. 

The diamond was the key to AC Milan's success. Mark van Bommel completely nullified Aaron Ramsey and pressured Robin Van Persie, who was already having enough trouble dealing with the defensive class of Thiago Silva.

It also denied Mikel Arteta the possession needed to influence the match and left Tomas Rosicky without many targets every time he ended up with the ball.

Without a midfield, Arsenal were neutralized entirely on offense, as RVP was starved of any decent service that might have allowed him to carve out a scoring opportunity.

On the other hand, on offense, AC Milan's diamond allowed AC Milan to pass the ball intelligently and effectively and allowed their attacking trio, Kevin-Price Boateng, Ibrahimovic and Robinho, to all bag goals and terrorize Arsenal's midfield.

It was very well played by the AC Milan manager, who's victory over Arsenal by such an emphatic margin will surely rank as one of his greatest achievements.

Tomas Rosicky Instead of Alex Oxlade-Chamberlain?

Any football fan who looked at Arsenal's lineup for this game probably asked the same question.

For some reason, Arsene Wenger believes that Alex Oxlade-Chamberlain is not yet ready to be a 90-minute player in Arsenal's biggest games.

This despite the fact that he's been easily Arsenal's second-most influential player (after Robin Van Persie) in the last couple of weeks.

On the other hand, Wenger has some strange attachment to Tomas Rosicky, believing him to still be the Czech magician he was when he first transferred to Arsenal. But the truth is that Tomas Rosicky has never recovered the ability that made him a world-class player since missing the entire 2008-09 season.

Rosicky is still good enough to act as injury cover for Arsenal in matches against the smaller teams of the EPL, but he's no Ryan Giggs.

To play him against the best teams of Europe in a crucial first leg tie away from home, in what is arguably your team's biggest match of the season, is plainly ridiculous.

Against AC Milan, Tomas Rosicky's only meaningful contribution was taking a half-decent shot two minutes into the game that went wide of AC Milan's goal.

After that, he was largely a passenger in midfield and did practically nothing to stop AC Milan from dominating Arsenal's midfield.

Meanwhile, in his 28 minutes or so on the pitch, Alex Oxlade-Chamberlain was able to get at least a couple of decent crosses into the box, one of which created a good scoring opportunity for RVP.

His trickery could not lift his team after they were down four goals to nil. But, had he been allowed to influence the game from the very start, I'm 100 percent positive Arsenal would've left Milan with a very different scoreline than the one they suffered this Wednesday.

Zlatan Ibrahimovic Is No Mr. February

In the buildup to AC Milan's matchup with Arsenal, much was made of Zlatan Ibrahimovic's inability to come up big in his team's biggest games.

In particular, one Goal.com writer chose to focus on Ibrahimovic's poor record in the month of February over the span of his career, especially in light of his three-match domestic suspension for slapping Napoli defender Salvatore Aronica.

Well, today, Ibrahimovic emphatically proved that the month of February has nothing on him.

Against Arsenal, Ibrahimovic tore apart the Gunners defense, assisting the second and third goals before putting the icing on the cake by scoring a fourth goal from the penalty spot.

There was a suspicion of offside in Zlatan Ibrahimovic's positioning in the buildup to AC Milan's second goal, but take nothing away from Ibrahimovic; this was his game and a top-class performance from one of the best strikers in the world.

Robinho? Where'd You Come From?

Robinho has not had a good season this year. Prior to this game, Robinho had scored only six goals in 28 matches, despite playing as a striker in nearly all those matches.

But today, Robinho looked back to his best. His first goal was put on a platter for him by Ibrahimovic, but his second goal required a decent amount of work and a good shot to get past Arsenal's goalkeeper.

Robinho didn't take over the game, but he was in the right place in the right time, and Massimo Allegri's confidence in the striker must surely be restored to a degree after a good performance against Arsenal.

Arsenal's Defense Is Very Vulnerable...But Not Because of Laurent Koscielny

Even though Arsenal's first-choice defender was available for today's match, they still conceded four goals and were largely dominated by AC Milan's forwards (and Kevin-Prince Boateng).

But one defender, Laurent Koscielny, was not at fault. In fact, when Koscielny was taken off near halftime due to an injury, I felt sorry for him because he was the one defender not at fault in the match up to that point.

In the buildup to AC Milan's second goal, if Ibrahimovic was onside, it was not because of Koscielny. And many times in the first half, Koscielny bailed out Thomas Vermaelen as the Belgian had an uncharacteristically bad game back in his natural position of center back.

Arsenal really will need to go back to the drawing board with their defense and work out the many miscommunications that took place today. But they can at least know that one member of their defense, Koscielny, is on his way to being one of the best center backs in world football.

Where to from Here?

After Arsenal's most painful defeat of the season (the 8-2 loss to Manchester United sucked, but its consequences weren't nearly as bad as those from this loss), Arsenal will likely need to re-evaluate their season goals.

I won't rule out an Arsenal comeback. But, at the risk of getting scolded by a hoard of angry Gunners, realistically Arsenal's chances of continuing in the Champions League are very, very slim.

If Arsenal wish to avoid a seventh consecutive trophy-less season, they'll need to focus their attention on winning the FA Cup and securing fourth place with the hope of taking a stronger team to next year's Champions League.

That way, they can still achieve success in a season teetering on possibly becoming one of Wenger's worst seasons as Arsenal's manager.

Meanwhile, for AC Milan, the future looks very bright.

Many people respected AC Milan as a team, but not too many looked upon them as Champions League contenders. With this win, though, they have to be considered contenders for the big prize.

Let's not forget how close the matches against Barcelona were and how strong this team is when all of its first-choice players are fit.

They may have had a few bumps in their season thus far (such as losing to Juventus on two separate occasions). But they're still active in all competitions and have a very good chance of securing at least one piece of silverware by the end of the season.