#4 An inverted midfield setup
Allegri used a plethora of formations at Juventus, most renowned among them the 3-5-2 and the 4-2-3-1 formations. In the last couple of years, the former Juve coach abandoned the former formation in favor of using variants of latter, which mostly included the 4-5-1 or 4-2-1-2-1 formations. The emphasis was on defensive solidity first and attacking output later.
This outlook eventually crippled Ronaldo who was not able to replicate his goalscoring exploits with Madrid at the Old Lady. Sarri will seek to espouse a more free flowing midfield which will offer greater attacking channels for the forwards to exploit. His Juve formation will resemble somewhat of a 4-3-3 formation with an inverted midfield structure.
Sarri typically prefers a regista against an all out defensive midfielder in this system. The regista sits at the base of the defense, prompting the central defenders to split up and the fullbacks to stay on the lines, such a tactic allows great passing lanes if employed using technically adept personnel.
Jorginho played the role to variable degrees of success at both Napoli and Chelsea. Miralem Pjanic offers similar dynamism at Juventus and is expected to occupy the position. Alongside him on either side will sit an attacking midfielder to assist in the attacking transition and an engine to break up the play, and carry the ball to the frontline. Mateo Kovavcic and Marik Hamsik played the former role, while Kante and Allan played the latter role, at his former clubs.
Blaise Matuidi and Aaron Ramsey offer similar characteristic abilities to the team and should slot into this system. Ramsey offers meticulous craft in exchanging passes while Matuidi is skilled at breaking up opposition plays and running with the ball forward.