How Inzaghi rebuilt the best back five in Italy

The numbers, first

Nineteen goals in 34 league games. Four consecutive 1-0 home wins. Yann Sommer posting the lowest goals-against per 90 minutes in Serie A. These are not the numbers of a team that got lucky with a soft draw or rode a hot goalkeeper through a purple patch. They are the product of a system that has been stress-tested, broken, and rebuilt — and is now running cleaner than it ever has.

Sommer, 36 years old and apparently immune to the concept of decline, is the last line of a back five that barely needs him. When he does act, it tends to matter. When he doesn't, it's because Alessandro Bastoni, Francesco Acerbi, and Stefan de Vrij have already dealt with the problem two phases earlier.

What Inzaghi actually changed

The story of Inter's defence in 2024-25 is partly about personnel and partly about trust. "Inzaghi gave the wing-backs more licence to press high because he became more confident the centre-backs could hold a line without a safety net," says Gianluigi Longhi, who covers Inter for Corriere dello Sport. "That sounds simple. It took two years to get there."

The back five is not new — Inzaghi has always preferred it — but the version running now is more compact in transition and more aggressive in the press trigger than the one that won the Scudetto in 2023-24. Denzel Dumfries on the right and Federico Dimarco on the left are operating almost as hybrid midfielders when Inter have the ball, and as a genuine second line of defence when they don't. The distances between the lines have been trimmed. The shape holds longer.

"What changed most is the team's ability to defend without the ball as a unit, not just as a back five," says Marta Casadei of La Gazzetta dello Sport. "Lautaro, Thuram, the midfielders — they all press from the front now in a way that makes the defensive job easier. Inzaghi convinced them the shape only works if everyone buys in from the top."

The Acerbi question nobody wants to answer

There is an elephant in the room — or rather, a centre-back. Francesco Acerbi missed significant time this season through injury and returned to find his place under genuine pressure. He has, quietly, been one of the most important figures in Inter's defensive record since February. He reads the game at a pace that makes his 37 years feel irrelevant. He also communicates constantly — Longhi describes him as "the conductor" when Inter are defending set-pieces.

Acerbi does not celebrate. He points. He organises. He looks at the floor for four full seconds after a goal is disallowed and then gets back into position.

Four days from Parma

If Inter beat Parma on Sunday, the title is theirs. The occasion will be loud and emotional and Inzaghi will probably cry — he usually does, and it is never embarrassing, always earned. But the real story will be in the shape: the back five holding its line, Sommer barely tested, the wing-backs already pushing forward before the final whistle.

Nineteen goals conceded. Thirty-four games. A defence rebuilt not with money but with method. Parma will need to find a way through something that Serie A, for the better part of a season, simply has not been able to crack.