Barcelona faced Tottenham Hotspur in their second Champions League group stage fixture at Wembley Stadium.

Both teams came into the fixture dealing with the loss of multiple players due to injury coupled with the ups and downs of league games so far this season. Tottenham were without Christian Eriksen, Mousa Dembele, Serge Aurier and Dele Alli. Barcelona would have a major test for their backline considering the absences of Samuel Umtiti and Sergi Roberto. Even with the significant injures, a loss for either team would be massive heading into the upcoming international break. From Barca’s perspective, anything but a win was the only option considering their recent La Liga struggles

Aside from the rotations in the backline due to injuries, the only moves Ernesto Valverde made to the starting lineup was replacing Ousmane Dembele with Arthur. In effect, Philippe Coutinho played his second consecutive game as a left winger while Arthur made his first ever Champions League start. The move was a rational decision by Valverde considering Dembele had featured in all nine of Barca’s games this season coupled with the fact that Coutinho had tremendous success as a left winger in the Athletic Bilbao fixture after Messi was brought into the game.

In this formation, Valverde still kept the same 4-3-3 shape as he focused on beating Tottenham with physicality and speed in the middle. Thus, Rakitic stayed on the right side of the pitch to balance out play when Messi drifts inside while Arthur moved out left to link with Coutinho and Alba but they often switched throughout the game.

Right from the start of the game, Messi picked up where he left off from the Bilbao fixture. In that game, Valverde brought Messi into the game not to play as a winger but rather as an attacking midfielder. This gave Messi more opportunities to run into space as well as create for Dembele, Suarez and Coutinho up front.

See here how Messi dribbles upfield and immediately has three options in front of him.

Now see how it all plays out with Messi delivering a cutting pass to Alba, who will then subsequently assist Coutinho for the goal to go up 1-0.

The goal was a major sigh of relief for Barca as it allowed them to relax as they aimed to reassure their dominance in the midfield, which was arguably the most notable theme of the first half.

In the absence of Alli and Eriksen, Tottenham lacked the speed and creativity to break in between the lines. Typically, both players are able to accelerate the ball upfield into threatening areas on the pitch, especially in counter-attacks. Without them, Tottenham’s 4-2-3-1 formation became much narrower than usual with full-backs Ben Davies and Kieran Trippier becoming the only reliable options to play on the flanks.

Thus, Tottenham were forced to build-up the majority of their play inside, which they evidently struggled to do so. The midfield trio of Rakitic, Busquets and Arthur had a heavy workrate in the first half as they pressed and worked to recover possession away from Tottenham. In effect, Tottenham had a difficult time building up a quick goalscoring opportunity because of the breakdowns caused by Barca’s midfield.

See here how Tottenham maintained possession for mere seconds due to the press orchestrated by Arthur and Busquets. They converge on the left side of the pitch to tackle and win back possession.

On this play, Lucas Moura is able to recover possession in the middle third of the pitch but the pressure from Busquets closes up space as he successfully executes a slide tackle to win back possession.

And on this play, Messi, Busquets and Arthur collectively press Wanyama and are immediately able to win back possession.

Tottenham lacked the cohesiveness in midfield to truly make an impact in the middle and attacking third. As a result, they were often forced to retreat into their own defensive half to regroup and start the build-up all over again. This was primarily due to Barca defending in a 4-4-2 formation with Messi and Suarez moving across the pitch to assist in the team pressing. Barca were able to congest Tottenham’s midfield with ease and shutdown any available passing lanes.

Due to Barca’s effective team pressing, Tottenham were dispossessed nine times in the first half and only recorded one shot, which came off of a low-percentage, outside the box shot by Harry Kane in the 24th minute. With the inability to string together passes in the attacking third coupled with the defensive traps enforced by Barca, Tottenham just could not get going in the first half.

In terms of the pressing and defending, it was Barca’s best performance in any half this season.

Now when Barca maintained possession, they also had to deal with Tottenham’s team high press. Although it was not as effective as Barca’s, it did force Barca to make some adjustments to move the ball upfield. When Barca were beginning to build out play from the back, Arthur and Messi often dropped deep to bring support to the backline.

See here in this sequence of how both Arthur and Messi drop deep to counter Tottenham’s high press in order to bring the ball upfield.

In other instances, all it took was individual skill to neutralize Tottenham’s press as seen here with Arthur’s ability to maneuver out of tight space. It earned him applause from the Wembley crowd.

From the pressing and defending standpoint, Barca were near flawless. When in possession, they responded well to Tottenham’s press as they maintained possession for 65% of the time in the first half coupled with the two goals but they lacked the fluidity to continually force their way in Tottenham’s box.

Heading into the second half, Pochettino had to find a way to counter Barca’s tight press while Valverde hoped to keep the same tempo that dominated the first half.

Ultimately, Tottenham’s best option to get back into the game would be on counter-attacks. They had to find a way to pace upfield with Lamela or Son and look to supply Kane with goalscoring chances. Pochettino’s gameplan switched from press and maintain possession to press and counter. It was arguably their only way to get back into the game. In the end, this paid off with a goal by Kane that came from a counter created in seconds.

But the celebration was short-lived due to Messi’s goal that was created solely from his off-ball movement.

Throughout the second half, Messi became increasingly accustomed to being stationed in the middle behind Suarez, which often left Semedo isolated out wide. Thus, Tottenham focused more on pressing in the middle portions of the pitch to jumpstart counter-attacks. Not only were they more aggressive in their press but more Tottenham players accelerated upfield whenever they were able to win back possession.

To counter this, Valverde went with the more conservative approach of slowing down the pace of the game and defending much deeper, especially in their own defensive third. This tactic was the main reason as to why Lamela had so much space outside of the box in his goal.

Valverde’s decision to defend deeper was a questionable decision considering Barca’s success in the first half. As alluded to before, Tottenham had a difficult time generating goalscoring chances in the opening 45 minutes of the game because Barca’s midfield and backline pressed and congested the middle third of the pitch. When in possession, Barca forced Tottenham to move multiple players across the pitch to press due to their quick passes.

But by electing to defend deeper and diminishing the pressing in the middle third during the second half, Tottenham would have much more space to work with to build-up an attack. They began to move the ball faster and with purpose to the point where it seemed inevitable that they were going to score the game-tying goal. But Messi scored the fourth goal in the 90th minute to put the game away and save Valverde from a tactical collapse.

Overall, Barca did just enough to deserve the win and move to 2-0-0 in their Champions League group.

From Valverde’s perspective, there is so much to learn from this game. Coutinho proved once again that he can be a reliable player when positioned as a left winger, which led to excellent chemistry with Alba. Arthur had by far his best performance for Barca as he essentially continued where he left off at Gremio -- short, compact passes while responding well to an opponent’s press. The backline had an effective performance although they struggled in the second half due to Valverde’s decision to defend deep. And once again, Messi was the difference maker with two goals and four goalscoring chances created.

Next up for Barcelona is an away La Liga fixture against Valencia.