Analysis

Arsenal Analysed: How we knocked out Porto

Leandro Trossard celebrates scoring against Porto

Our Champions League last-16 second leg against Porto was a tense, nailbiting affair that saw us edge past our opponents on penalties - but how did we do it?

If you were watching the game through your fingers or behind the sofa, Adrian Clarke has gone through all the footage and stats to discover some key reasons why we are now Champions League quarter-finalists.

Emotional control

This was a wonderful learning experience for our players, who came through a stern examination against one of the most streetwise, aggressive, and well-organised sides in Europe. When you consider Sergio Conceicao’s side also made 20 fouls but collected just a single yellow card, the Gunners also deserve credit for keeping their emotions in check and concentrating on the job in hand.

The Portuguese outfit did produce another outstanding defensive display, packed with discipline and resilience. Working insatiably hard to shut down space for us to play inside their half, the two-time European champions did a fantastic job of limiting our attacking threat. But in a sign that this team is growing in maturity, Mikel Arteta’s men remained patient, never falling into the trap of chasing the game by taking reckless or unnecessary risks.

By the time the final whistle blew after extra-time, the visitors’ expected goals metric stood at just 0.52. There were one or two breakaways to deal with, but we were always the side in control.

Our emotional intelligence was top class all evening, and this was showcased brilliantly with the clear-minded approach of all four penalty takers, who coolly dispatched their spot kicks in emphatic fashion.

Bukayo Saka’s crisply struck penalty was especially eye-catching, as he generated more power than he usually does from 12 yards. As shown below, he also opted to pick a spot in the opposite corner from his previous five penalties:

Bukayo Saka's penalty against Porto
A map showing Bukayo Saka's previous five penalties

Odegaard’s inspired assist

This was a captain’s performance from beginning to end by Martin Odegaard, who didn’t stop running, with and without the ball. He also supplied the moment of genius that we needed to level the tie on aggregate, with one of the finest assists you will see all season in the Champions League.

In this timeline below, you can see how our playmaker was faced up by a wall of four Porto defenders on the edge of the box:

The move showing Martin Odegaard's assist against Porto

His first shimmy and touch took the ball past one opponent, but the quartet was not broken and still blocked his path:

The move showing Martin Odegaard's assist against Porto

Thankfully his second piece of skill, quickly shifting the ball past another defender, was the move that made the difference, drawing No.23 Joao Mario towards the ball and away from Leandro Trossard:

The move showing Martin Odegaard's assist against Porto

The weight of the pass was impeccable, and Trossard matched that quality with a supremely accurate touch and finish to find the bottom corner. To prise open this stubbon back four, we needed a moment of magic, and Odegaard came up with that vital piece of imagination.

Lessons learned

Arsenal made some key improvements from a frustrating first leg that saw us fail to register a shot on target. Our tempo was much higher in possession, helping us stretch the visitors and put them on the back foot with greater regularity, and thanks to a great effort from our ball kid team, we prevented the Portuguese giants from having breathers and made it less of a stop-start affair.

The key change from a tactical perspective was how we identified a weakness in Conceicao’s defensive framework, and subsequently exploited it. Whenever we built down one wing and set the ball back to teammates around the edge of the box, 41-year-old Pepe and his fellow defenders had a habit of being caught holding a deep line. Failing to squeeze up quickly, this created a pocket of space behind the Porto players who went to press. 

This example from early on shows the wide open hole, and on this occasion Odegaard got on the end of a pass before being crowded out:

An example of Arsenal finding space behind Porto's defence

In the second half a similar situation arose, with Pepe and co caught too deep and a vacuum of space opening on the right side of the penalty box. Here, Saka was played in by Eddie Nketiah and had an effort on goal:

An example of Arsenal finding space behind Porto's defence

The clearest example came from the goal itself, when one set of opposition players were attracted to the ball, while the three other defenders sat in a rather detached line that covered the width of the goalposts. This left room for Odegaard to slip Trossard in, and because they were also deep there was no danger of him being offside.

An example of Arsenal finding space behind Porto's defence

Studying the opposition and their habits in detail paid off, as this type of move was by some distance the strategy that proved most successful against a very well-drilled side.

Raya the hero!

David Raya has an incredible spring, and he used it to great effect to become our penalty shootout hero. Making his mind up early, he pushed off to his left with rapid force to beat away spot kicks from Wendell and Galeno.

While his first save was a feather touch to deflect the ball onto the post, his match-winning stop from Galeno was almost identical to the way he denied West Ham's Said Benrahma at Emirates Stadium in December. It is fast becoming his trademark save.

David Raya saving Said Benrhama's penalty against West Ham
David Raya saves the crucial penalty in the shootout win over Porto

Raya had looked an assuring presence throughout this encounter, making two excellent stops in normal time, both diving to his left as well. His temperament, decision-making, and distribution were all excellent in a pressure cooker atmosphere, so it was fitting the Spaniard produced such a memorable, match-winning moment.

Following on from Declan Rice’s goal at home to Manchester United and Kai Havertz’s winner at Brentford, our loan signing now has that first major contribution under his belt that every new signing craves. It was also a majestic save that took us to our first  Champions League quarter-final in 14 years.