The case for Sandro Tonali at £92.5m guaranteed (plus up to £7.5m in add-ons) does not begin with the fee. It begins with what De Zerbi's system needs in the midfield and whether Tonali is the player who provides it.
The short version: De Zerbi builds teams around possession from the back, baiting the opposition into pressing high and then exploiting the spaces behind that press with vertical, incisive midfield play. The position requires a midfielder who can do three things simultaneously and well — protect the ball under pressure, drive vertically into space, and arrive late in the box to contribute goals from midfield positions. Not all midfielders who do one of these things do the others.
Not all midfielders who can protect the ball under pressure can also drive vertically and arrive late in the box. Tonali does all three.
His background tells you a lot about why De Zerbi wanted him specifically. Brescia, AC Milan, then Newcastle United, where he operated in a more defensive role than his best work at Milan had required. Howe's system asked the midfield to screen and to cover rather than to carry and create. Tonali is capable of screening — he is a strong defensive midfielder when the situation demands — but he is a categorically different player when given licence to drive forward. De Zerbi's system at Brighton asked this of Mac Allister and Caicedo in tandem. At Spurs, the expectation is that Tonali, alongside Mateus Fernandes and Conor Gallagher in a midfield three or two, provides this profile with a higher technical ceiling than De Zerbi has previously had available.
Fernandes, 21, signed from relegated West Ham for £85m, offers energy and technical quality in a profile that overlaps with Tonali's in some ways and complements it in others. At 21, in a system this demanding, Fernandes should be understood as mid-integration. He will improve within the structure rather than arriving as a finished product. Gallagher, signed from Atletico Madrid in January for £34m, has Premier League experience and the physicality the midfield needs in transitional phases. Between the three of them, De Zerbi has options — a pressing engine, a ball-carrier, and a box-to-box runner — which is exactly the kind of functional variety a system this intense requires across a full season.
Saturday's home fixture against Newcastle is a useful early test of the midfield argument. Newcastle retain Bruno Guimaraes as their midfield anchor, one of the Premier League's most complete central midfielders — a player who does, in fact, do most of the same things Tonali is being asked to do, and has been doing them consistently in the English top flight for several seasons. The contest between Guimaraes and Tottenham's new midfield structure is the most instructive tactical dimension of the match. If Spurs can match Newcastle's intensity and control possession with the same fluency that Guimaraes brings for the away side, the system is working. If Newcastle dominate the midfield battle, De Zerbi has real work to do.
The centre-back situation adds another layer of complexity. Cristian Romero's departure this summer — Fabrizio Romano confirmed weeks ago that it was 'very clear Cuti Romero is going to leave' — means De Zerbi goes into this opener with Marcos Senesi and Jan Paul van Hecke as his first-choice pairing. Van Hecke worked directly under De Zerbi at Brighton, which matters: he already knows what the system asks of a centre-back in possession, how to step into midfield lines, and when to hold. Senesi brings four solid seasons and 128 appearances from Bournemouth, which is not a bad CV for a free transfer, but this is his first game in a system that demands far more with the ball than anything he has previously been asked to produce. The Romero-shaped hole is real, and it will take time to assess how much it costs them.
Micky van de Ven, described by those close to the club as absolutely untouchable in De Zerbi's thinking, is unavailable for the opener due to limited preseason minutes. That absence matters. Van de Ven's carrying ability from deep is tailor-made for this system — he is one of the fastest ball-progressing defenders in the league and gives De Zerbi a genuine extra option in buildup. His reintegration into the starting XI over the next month will be one of the more significant tactical developments of the early season.
Set pieces are also relevant for this specific fixture. Newcastle under Howe are one of the league's more dangerous sides from dead balls, and they execute that threat systematically — it is not incidental. The Senesi-van Hecke pairing faces their first genuine aerial challenge of the season from a team that has specifically designed this part of their game to hurt you. Kinsky's ability to command his box under pressure matters here, and it is one of the things Saturday will tell us about the goalkeeper in a competitive context.
Robertson at left back provides an outlet the system uses heavily: overlapping runs that give Tonali and the midfield a short-combination option out of pressure. At 32, Robertson is not being asked to make 40 overlapping runs a game — that ship sailed at Anfield. He is being asked to make the right ones, at the right moments, with delivery that causes problems. That is a more manageable ask across a full season, and it is the ask De Zerbi has specifically designed the role around. Robertson's football intelligence, built over nine years and 378 appearances at Liverpool, is arguably more valuable to this system than his legs ever were.
The honest version of the tactical case for all of this is that it takes time. The first three or four games of any De Zerbi side historically look less polished than what develops over two or three months of work together. Brighton in his first season, Marseille in his first months — the early games are not the advertisement. The spending this summer is a statement of intent and a genuine upgrade in personnel. It is not a guarantee of immediate output. What Saturday tells us is whether the foundations are solid enough to build on — not whether the building is finished.
Here is what you should take from this: Tonali was not bought to be decorative. He was bought because De Zerbi identified a specific gap in what his system needs and went and got the player who fills it most completely. The fee is enormous. The logic behind it is not hard to follow once you understand what the system actually asks. Whether the player, the midfield, and the manager can work through a difficult early period to get there is the real question. Newcastle at home, on the first Saturday of the season, is where we start finding out.