Chelsea are much further along the learning curve for the offensive side of Maurizio Sarri’s schema than the defensive side. The full-backs take the fall for what happens – and does not happen – in front of them.
Marcos Alonso kept up his winger-like goal creation for Chelsea by assisting on Pedro’s opener and scoring the winning goal against Arsenal. Alonso looked more like a winger than a fullback on both goals he had a hand in, driving the ball forward on a counter-attack before squaring it to Pedro and then scoring his own on an angled run into the six yard box.
If only Chelsea’s wingers could do both sides of their job as effectively as Marcos Alonso does both sides (and more) of his.
Chelsea’s wingers are enjoying the space and speed of Maurizio Sarri’s tactics. However, they are not enjoying Sarri-ball responsibly. For the system to work the wingers need to cover their fullbacks by tracking back as soon as they pull off the press.
The high line and high press leaves a no-man’s-land between the wingers and the full-backs. If the full-backs move up to close that space, they surrender even more space behind them. This gives a free channel for the opponent to counter-attack and overrun the two centre-backs from either side and the centre. If the full-backs drop back into this space, though, knowing their wingers will not cover them, they give up enough space between the lines for the opponent to build momentum and set their own shape on offence.
Chelsea’s left side has a string of disadvantages. Willian is far less diligent in tracking back and less efficient in recovering from the press than Pedro. Willian’s work rate is woefully overrated, inasmuch as it is almost completely dependent on the direction of play. The Blues also have Ross Barkley covering the left side of the midfield, while N’Golo Kante is on the right. And on defence, Chelsea’s most defensive full-back is on the right while their more attacking full-back is on the left. Maurizio Sarri likes this asymmetry between his full-backs, and Chelsea’s personnel map onto it perfectly. But it further adds to the overall imbalance between the left and right.
Arsenal attacked Chelsea’s left side not because Marcos Alonso is slow or has poor positioning, as his indefatigable critics insist. The Gunners targeted the left because that side has a one-way winger, a one-way midfielder and the more offence-minded full-back. And Arsenal’s right is the faster of their flanks, courtesy of full-back Hector Bellerin.
Antonio Conte’s switch to the 3-4-3 freed up Chelsea’s wingers by widening the back-line with an extra centre-back and then supporting the wingers with the wing-backs. Marcos Alonso and Victor Moses could play the extreme width of the pitch without giving up the inside channels since there was an additional centre-back. The wingers had less responsibility to cover back because the wing-backs could more readily drop back into the defensive line.
Before Conte, Jose Mourinho simply insisted the wingers would all drop back to defend. There was less question of timing and triggers. Everyone knew their seat on the bus.
For all the excitement Maurizio Sarri’s methods generate for their offence, they are not neglectful on defence. In his three years at Napoli, his sides were always second or third in Serie A for both goals scored and goals allowed (and, not surprisingly, in the final table). For two of those three seasons, Napoli conceded fewer goals than Chelsea did when they won the Premier League in 2016/17. One of those seasons was Sarri’s first at Napoli. In 2015/16 Napoli gave up two goals in each of their first three games. They then kept clean sheets in seven of their next 11 games.
Chelsea could fix some of these issues with simple personnel changes. Eden Hazard’s return to the starting XI should send Willian to the bench. Hazard should be more diligent in tracking back than Willian, but Hazard will also distort the opposition as they try to play against him. Opposing teams will take fewer chances with Chelsea’s left, knowing how devastating he would be if they turn the ball over on his side of the pitch. Hazard and Alonso also developed a good chemistry on the left in the 3-4-3. If they can adapt that to the new formation and tactics they can strengthen the side.
Mateo Kovacic will also improve Chelsea’s left and reduce the left-right asymmetry. In his substitute appearance against Arsenal he showed attributes of both Hazard and N’Golo Kante. He will reinforce the left side of the midfield, which will provide Alonso with the cover his position needs and deserves.
As things stand now, Chelsea’s left side in Maurizio Sarri’s 4-3-3 is systemically weak defensively. This attracts the opponent’s offence, so while both full-backs are exposed when facing an attack, Marcos Alonso comes off looking the worse for wear. Alonso’s offence shined against Arsenal because everything on Chelsea’s left supports forward play.
Once Sarri figures out his squad and they master Sarri-ball, the Blues should grow out of these issues. Until then, Marcos Alonso will retain his usual role as designated scapegoat to go with his Man of the Match awards.