Arsenal vs. Chelsea: 6 Things We Learned

A much-changed Chelsea side strolled to a comfortable 2-0 victory at the Emirates Stadium on Tuesday in the League Cup fourth round, ending Arsenal's hopes of progressing further in the competition.

Cesar Azpilicueta latched onto Carl Jenkinson's poor header back to Lukasz Fabianski and slid home to score his first goal for the club, before Juan Mata's piledriver in the second half sealed the victory for Jose Mourinho's side.

The Blues were surprisingly comfortable for the majority of the game, despite making 10 changes from the 2-1 win over Manchester City at the weekend. Gary Cahill was the only survivor as Mourinho looked to rotate the squad.

Arsenal had also tinkered with their lineup. Mesut Ozil and Olivier Giroud dropped to the bench as Arsene Wenger attempted to give some fringe players a chance.

But the likes of Nicklas Bendtner rarely threatened, and the Gunners boss will be disappointed with the lack of fight that his side showed as the Blues cruised into the quarterfinal. 

And after the clash of the round came to a close, I looked into what we can take from the game.

Chelsea's squad depth is tremendous

Perhaps it's not exactly something we learned, but on Tuesday night, we saw the full extent of how having a big squad of players can pay dividends. 

Mourinho was faced with a fixture-list nightmare, having to prepare his side for another match just 48 hours after their win over Manchester City. The Portuguese tactician refused to hide his dissatisfaction but soon realised there was nothing to be done other than rotate the squad.

For many sides, this would mean giving the young players, sourced from the Under-21 development squad, a chance to impress. But not for Mourinho.

There were players, full internationals even, who were itching to get a run out. Michael Essien, Kevin De Bruyne and Demba Ba had all been frozen out of the side before Tuesday night, but all three managed to get some valuable playing time.

Some say having a large squad can cause rifts within the team, but for Chelsea, the opposite effect seems to be occurring. Azpilicueta came in and put in a solid shift at right-back, pitching in with his first goal for the club. And the very fact that Mourinho could bring on another international, Czech defender Tomas Kalas, so late on was a big kick in the teeth for Arsenal, who had 18-year-old rookie Isaac Hayden on the bench. 

The contribution of the so-called "fringe players" will have given Mourinho food for thought as he ponders the squad for the Newcastle game. It is a selection dilemma, of course, but for the right reasons.

Arsenal should have signed Ba and let Bendtner leave

On Tuesday, it became all too clear why Arsenal were so keen to let Danish international striker Bendtner leave in the summer. The towering forward looked weeks short of fitness and cut a forlorn figure in attack as he struggled to impose himself on the game.

And when he did get the opportunity to go for goal, the 25-year-old looked so far short of confidence that he passed back to Aaron Ramsey, even though he had the goal at his mercy. 

Arsenal supporters may question the Dane's inclusion, but Wenger was right to give him some playing time. However, after eight years without a trophy, could the Frenchman risk playing a striker who has not scored since 2011 for Arsenal?

Giroud seemed the obvious choice for the centre-forward position to start with, and if the Gunners were in a position to rest their star striker, Bendtner could have then entered the fray. What was more frustrating was to see a striker of Ba's quality sitting on the bench and not making an appearance until the final stages of the game.

It's clear that Wenger needs to sign another striker in January, because time is running out for Bendtner to save his career at the Emirates Stadium.

Juan Mata is a class act

No matter how hard he might try to knock down Mata, Mourinho cannot deny that the Spaniard has handled himself brilliantly in the past few months. 

The 25-year-old was in stunning form in North London, dropping into pockets of space and constantly working back to help the team in difficult situations. It was almost as if he was showing the improvement in his game to Mourinho in the hope that the manager would be satisfied with what he saw.

And he was, evidently, just like the rest of us.

Even in the post-match interview, per Sky Sports, Mata refused to talk himself up and praised his teammate and close friend Azpilicueta on his goal: "I'm more happy for Cesar, to be honest. He trains more than anyone and he fully deserves the goal and the celebration more than anything."

It would appear that his class on the pitch is well-matched by his off-field character. 

Arsenal are beatable

It may not seem obvious and is perhaps insignificant due to the side that Wenger put out, but Tuesday's result could be the start of a nervy period for Arsenal.

Chelsea went into the game on a high and left feeling exuberant after their emphatic victory. Arsenal, on the other hand, need to ensure they pick themselves up and get a good result at home to Liverpool on Saturday.

The sign of a champion is never knowing when they are beaten, and when they finally are, knowing how to bounce back. It remains to be seen whether the likes of Ozil and Ramsey can lead the side through the darkness and back to winning ways. 

With a tough list of fixtures coming up, league leaders Arsenal must concentrate on returning to form by overcoming a close rival in Liverpool, but it will not be easy.

Carl Jenkinson needs time

The young full-back looked nervous on the right hand side, failing to make the surging, energetic runs down the flank that would have caused Ryan Bertrand a few problems. 

Instead, he was affected by his early error, misjudging the pace on his header as Azpilicueta capitalised to score. The lack of togetherness at that point meant that Jenkinson was left to dwell on his error, and with the help of 9,000 Chelsea fans, he was made to remember it throughout the game.

He looked as if he did not possess one ounce of confidence, and he may need a break with the Under-21 squad to build it back up again after his below-par performance. It's not the end of his meteoric rise to the top, but it's a hindrance.

Mourinho has the squad's backing

If it wasn't clear before, the Chelsea players should now be aware that their 50-year-old coach knows what he is doing. Whether it's the pre-match mind games, the shuffling of the pack with 10 changes or starting with a right-back in the left-back position, these things no longer matter. The players trust Mourinho; that was evident on Tuesday evening.

Willian was one of those given a rare start, and the Brazilian excelled in the midfield, producing some lovely pieces of footwork and providing the assist for Mata's goal. De Bruyne was back in the side and tried to make an impact, but he was withdrawn midway through the second half. There was no sign of a tantrum this time.

He even had the confidence to leave key players such as John Terry, Frank Lampard and Oscar at home, and that amount of faith placed in the squad is sure to have given them extra belief.

With more results like this, you would have to consider Chelsea as one of the contenders for the trophy.