Barcelona take an early lead
In the opening minutes of the game, Barcelona took an early lead through moving the ball from side-to-side, forcing Chelsea back, before quick combinations and defection inside the box saw Lionel Messi score.
Chelsea tried to hold a high line from the initial kickoff, but were unable to find a way to press forward in order to maintain and push Barcelona back into their own half. Barcelona passed from side-to-side to find spaces on the outside, which would result with Chelsea’s backline dropping back.
Barcelona found paces on the outside since Alba moved up from left back to the left wing of the frontline and Ousmane Dembélé was high and wide on the right — pinning Chelsea’s wing-backs deep. Along with right-back Sergi Roberto moving inside to join the midfield line and find space on the outside — Barcelona’s one change from the first leg being Dembélé for midfielder Paulinho — Messi would drop to find space on the outside or ahead of Chelsea’s midfield four (sometimes switching with Dembélé) in order to receive the ball, and Andrés Iniesta would receive and hold the ball on the left, with Luis Suárez moving to receive to feet before running behind the inside of Victor Moses.
Chelsea continued to try to hold their high backline from midfield, and pushed to the sides to press when Barcelona passed back. They won the ball in midfield upon Barcelona’s forward passes to the frontline, and could sustain attacks around Barcelona’s box, where the front three would combine (although their combinations at times were played too quickly). Willian and Eden Hazard could move to the sides and dribble with the ball as switches found the wing-backs in space to cross the ball into the box, and Chelsea could win set pieces.
By playing higher up they could then go on to recover the ball in midfield when Barcelona attempted to counter and play long from the back, where the backline could win the first ball in the air before the midfielders picked up loose second balls — only for Messi to win the ball on one occasion, which resulted with Barcelona scoring their second.
When Chelsea had the ball deep in their own half, either after winning the ball or building possession Barcelona would always try to pressure high, especially through the middle. Chelsea managed these situations well for the most part when they were careful about playing forward passes into pressure (especially into the wing-backs).
N’Golo Kanté, Willian and Hazard could dribble out and past pressure from midfield starting attacks and counters, with the Brazilian constantly causing problems as he carried at speed. It also helped having Olivier Giroud as a reliable option to go long, bypass Barcelona’s midfield and start quick attacks against their backline upon winning the second ball.
Barcelona managed the game well when they were able to hold on to the ball and force Chelsea to drop back to midfield as they could circulate the ball in order to kill time and wait for openings to create. This forced Chelsea to be patient to pick the right moments where they could approach to press or recover the ball.
In the second half Chelsea were able to maintain a high position with the ball and create a number of opportunities from wide areas, both through direct and long switches or playing combinations in the middle between the front three before finding a spare man on the outside. However, even when they found Marcos Alonso free on the outside, Dembélé was quick and alert enough to recover back each time.
Hazard and Willian moved wide to take on the defenders and put crosses into the box more consistently, but finding a successful pass into the box continued to be a task too difficult for Chelsea to achieve.
Barcelona made early changes with Paulinho and André Gomes replacing Iniesta and Sergio Busquets (the latter forced), which weakened the Catalans with a lot of time left. This provided a great opportunity for Chelsea as they continued their high play.
However, just as Chelsea’s chances increased, Barcelona won the ball from Azpilicueta’s attempt to play forward and scored their third of the match through Messi.
Chelsea’s changes were to increase the mobility at the front with Morata and to try to have a similar change as they have in the past with Zappacosta replacing Moses when the latter hasn’t had success with delivery, but with little gained.
Barcelona’s advantage from the first leg and their early goal in this game allowed them to be able to wait for openings when Chelsea made a mistake or during counter attacks in order to create chances and extend their lead. Plus Messi scored or created all of their goals over the two legs, an impact which Chelsea had limited in the past.
Chelsea created a number of good opportunities and could sustain high play inside Barcelona’s half for prolonged periods, but couldn’t find a breakthrough as centre-backs Gerard Piqué and Samuel Umtiti made a number of vital blocks and clearances. As the Catalans weakened through their changes, there was a good chance for the Blues to get the result they needed had they managed to score. Unfortunately the hosts’ excellent defending and Messi’s clinical attacking saw them score a third goal to kill the game.