When Manchester United have the ball, they are aligned on the diagonal in a 4-3-3. You wouldn’t call Amad Diallo a wing-back, you would say he is playing right wing. This is another team that challenges the way we traditionally look at formations.

When you view United on the diagonal, Bruno Fernandes operates as a roaming box-to-box midfielder, closer to a number ten than a defensive midfielder. Mason Mount joins from the left to form a makeshift asymmetrical midfield three, with both he and Fernandes offering attacking thrust while Casemiro anchors behind them. Further forward, Matheus Cunha and Bryan Mbeumo have license to swap positions and drop deep, offering a passing option to feet or running beyond the opposition’s back line. On the far side, Amad Diallo acts as the main outlet, the target for the switch of play.

This concept of short-passing combinations and runs on the diagonal is not a new tactic for Ruben Amorim. He has addressed the concept of combining on the diagonal several times in Portuguese when he managed Sporting.

Following a match against Marítimo on January 8, 2023, Amorim explained in a post‑match press conference why he substituted centre‑back Coates with Gonçalo Inácio. Without Coates acting as a makeshift striker, Sporting tried to reach goal “with many short diagonals.” Amorim admitted the team’s finishing was poor: “Muitas diagonais curtas e depois aí teríamos de definir melhor, mas não era o nosso dia,” roughly translates to “many short diagonal passes, and then we’d have to finish [our chances] better, but it wasn’t our day.”

After a 0‑0 draw away to Manchester City on March 9, 2022, Amorim justified using Paulinho as a left‑sided forward. He said the striker is “very intelligent, very robust physically, and it was clear from the diagonal runs he made, linking up with Slimani.” He added that Paulinho’s runs off the flank provided a second reference point to hold up the ball, suggesting that diagonal movements from wide areas were part of the tactical plan.

When speaking English, however, his message sometimes gets lost in translation. As Amorim mentioned when his team was compared to Crystal Palace—a team that doesn’t organize on the diagonal but plays with a back five and use wingbacks—he said with a wry smile: “We play in a different way. And you can understand that by data. But now it’s hard to explain everything. But you don’t say that all 4-3-3 [teams] play in the same way, right? We play in a different moment, we defend in a different space, we try to attack in a different way.”

The players themselves are starting to grasp the common principles of play. After the 4-4 draw to Bournemouth, Amad Diallo explained that the structure “depends on the opponent. Sometimes we play in 4-4-2, sometimes in 3-4-3, and sometimes in 4-3-3. Maybe people outside don’t see it. We can change based on what Ruben [Amorim] asks of us. The system doesn’t matter to us.”

The concept of Diagonality is a hard thing to describe. If you aren’t looking for it you will miss it. It is a different way to look at a game. But when you see it you can’t unsee it, and other teams have shown it is effective.

How do you press a team that has their defenders on one side of the pitch and forwards on the other?

Even Bournemouth manager Andoni Iraola, whose team is heralded as one of the best high-pressing sides in the league, acknowledged the difficulty of pressing Amorim’s system: “They adapt depending on who you put to mark them. It’s a very flexible system.”

It’s hard to defend passes on the ground when players are aligned on the same diagonal, letting the ball run through their legs, using deception to progress with quick flicks and one-twos. One switch of play and you are caught with your pants down, fully exposed.

You have to assign roles to these players instead of positions to fully appreciate what they are doing, what they are actually trying to achieve instead of what we want them to achieve when we look at rigid formations in straight lines from back to front.

When Bukayo Saka tracks back for Arsenal, we don’t call him a wing-back, we call him a winger. The same applies here.

Amad Diallo tracks back to mark the left-back in defense, and cover for the right-back when the back post is open. But he isn’t good at tracking the ball or his man. He’s not blazing fast in a straight line like Bryan Mbeumo is. He’s alright in the duels but he’s not a player you’d want to have in the back-line.

Manchester United’s best defensive performance this season came against Brighton. It was the first game that Amad Diallo stayed further forward to mark the opposition’s left-back, Maxim De Cuyper.

Bryan Mbeumo was the one to track back and mark the speedy Yankuba Minteh, to defend the space beyond the back line when United lost the ball. He was better at sweeping in transition because of his pace and he’s better at tracking the ball.

United align on the diagonal from left to right. When they lose the ball, their right side is more exposed in transition. Either Mbeumo or Amad have to track back and sweep. The strong left side presses and covers while the weak far side sweeps until they regain control.

They stopped having Mbeumo track back against Everton because of a change in personnel. One side is always offensive and one side is defensive. Mazraoui, the right-back, is defensive and Dorgu, the left-back, is offensive. Since then they’ve abandoned having Mbeumo track back and the defensive performances have become mixed.

Is their execution always good? No, but they started to become more consistent attacking wise. Does their defense have enough quality? No, they don’t have enough quality in the center-back position. Are they the most entertaining attacking team in the Premier League? For me, still no question, yes.

But all of this comes with a massive disclaimer. Bryan Mbeumo and Amad Diallo will be going on international duty to the African Cup of Nations (AFCON) for several weeks. My guess is they’ll use Patrick Dorgu as the outlet on the left instead of Amad Diallo on the right, possibly organizing on the diagonal from right to left to compensate. While leaning heavily on vertical lofted passes into Benjamin Sesko and Joshua Zirkzee. The issue is they’ve never tried that without Bryan Mbeumo on the pitch. I’m very interested to see what they have planned and how much of a mess it will be.