Injuries force Amorim into back four as Milan visit struggling Udinese
Stripped of key defenders and midfielders, Milan abandon their usual back three for a patched-up back four at Udine, while hosts in freefall field a reshaped front line of their own.
Milan arrive at the Bluenergy Stadium missing so many bodies that Ruben Amorim has had to rebuild his side's shape from the back, according to Football Italia.
The visitors had looked to be finding rhythm, with three wins from four matches in all competitions before Thursday's Europa League trip to Bournemouth unravelled everything: Mike Maignan was sent off and Milan lost 3-0, with Adrien Rabiot, Diego Moreira and Mario Gila all picking up injuries in the process, Football Italia reports.
That trio joins Samuel Chukwueze, Matteo Gabbia, Alexis Saelemaekers and Pietro Terracciano on the sidelines, leaving Amorim short of specialists in exactly the areas his usual system depends on.
Why Milan's shape has changed, not just the names on it
Amorim has built his Milan sides around a back three with wing-backs providing the width, but the absences of Gabbia and Saelemaekers in particular leave him without the personnel to staff it properly.
Against Udinese he instead lines up with a flat back four of Fikayo Tomori, Koni De Winter, Strahinja Pavlovic and Sankhoun Diawara, with Davide Bartesaghi pushed higher up the pitch into a wide midfield role rather than his more natural full-back or wing-back slot.
That is a meaningful tactical adjustment rather than a cosmetic one: Bartesaghi now has to provide attacking width from a more advanced starting position, while Diawara is asked to cover the ground a specialist left-back or wing-back would normally occupy alone.
In midfield, Ardon Jashari is preferred to Ruben Loftus-Cheek to partner Luka Modric, giving Milan a double pivot built for control and progression rather than the extra attacking thrust Loftus-Cheek might have offered.
Christian Pulisic and Omari Hutchinson complete a front line alongside Goncalo Ramos, who has shaken off a knock to start up top after missing involvement elsewhere in the squad's recent injury list.
Udinese's collapse runs deeper than one scoreline
Udinese travel into this match on the back of five consecutive Serie A defeats, a sequence that culminated in a 3-0 home loss to Lecce last time out, Football Italia reports.
The club's injury list has grown alongside the results: Idrissa Gueye, Vakoun Bayo and Alessandro Zanoli are all unavailable, Oumar Solet did not even make the squad after failing a fitness test, and David Alaba - signed as a free agent - has now joined the absentees too.
Those losses strip Udinese of midfield experience and defensive depth at the same time their form has collapsed, which helps explain why Kosta Runjaic's side set up with Keinan Davis isolated as the lone central striker rather than risking a more expansive attacking look.
Davis gets support from Giorgi Chakvetadze and Jurgen Ekkelenkamp just behind him, a shape built to spring forward on the counter when possession is won rather than to dominate the ball against a Milan side still carrying more individual quality.
Nicolò Zaniolo returns to the matchday squad for the first time since the 1-0 defeat to Cagliari on 19 September, though only as a substitute option rather than a starter, which suggests the coaching staff are easing him back rather than trusting him with ninety minutes straight away.
What the selections suggest about each side's priorities
Milan's back four is a reaction to circumstance rather than a stated change in footballing philosophy, and the test for Amorim is whether De Winter and Pavlovic can defend central spaces without the extra cover a back three usually provides.
The presence of Jashari and Modric together in a double pivot points to a team prioritising control of midfield transitions over an extra attacking body, a sensible caution given how thin the squad now is in defence and the risk of further injuries compounding an already difficult run.
For Udinese, fielding Davis alone up front with Chakvetadze and Ekkelenkamp tucked in behind looks like an attempt to stay compact and limit the spaces Pulisic and Ramos can exploit, accepting a reduced attacking threat in exchange for defensive solidity against a visiting side still superior on paper.
Whether that approach can finally halt a five-match losing run will depend on Udinese's discipline without the ball, since any lapse in a patched-together back four and a makeshift Milan midfield is exactly the kind of opening a side in Udinese's position needs to find.
Kick-off at the Bluenergy Stadium is set for 19:45 GMT, with both clubs needing a response: Udinese to end their losing sequence, and Milan to show their earlier run of form was not simply undone by one chastening night in Bournemouth.