Among all the discussion of who Milan will be starting up front at the start of Serie A season (and whether Zlatan Ibrahimovic' will be one of the options) and who will be joining the Rossoneri at the back (Alessio Romagnoli still a reported target, but the saga is dragging out longer than the Police Academy franchise), not a lot of credence has been given to the midfield, the engine room.
Negotiations for a midfielder of proven quality (and no, Andrea Bertolacci does not yet fit that category, €20m aside) have somewhat stalled in light of the public romances of Ibrahimovic and Romagnoli so it appears, for now, Milan's 2015-16 starting midfield may be mostly similar to the one that finished the 2014-15 season.
Thankfully, Sulley Muntari is no longer an option (pause for raucous cheering) but the newly renewed Nigel De Jong, the newly healthy Riccardo Montolivo have returned for the season as has Giacomo Bonaventura, Keisuke Honda and Andrea Poli. Though this writer is desperately hoping Milan pull off a deal for someone like Axel Witsel, it's safe to assume that three spots in the middle will be taken up by at least two out the five mentioned. Jose Mauri of course is a talented prospect, but it's hard to envisage the youngster slotting in to the starting XI just yet.
At the base of the 4-3-1-2 lies the "regista" role, defined by Andrea Pirlo during his time under Carlo Ancelotti at Milan and formerly, Carlo Mazzone at Brescia. When a creative midfielder like Andrea was surrounded with hardworking players around him (Gennaro Gattuso next to him often doing the running of two or three players) there is enough space to spread the ball and make the typically narrow midfield diamond work. With effective and aggressive full-backs, it works very well.
Evidently, the closest thing Milan have to Andrea Pirlo is Riccardo Montolivo (stop laughing at the back). The Rossoneri captain has not often shown the form that made him such a precocious talent at Fiorentina operating in the same position, but partnered with Nigel De Jong in the mezz'ala role that Gennaro Gattuso made his own for the past decade and a half, Monty could have more space to work with than under previous coaches.
Another option is to hand the keys to Nigel De Jong, a "destroyer" in the Mark Van Bommel mould that Massimiliano Allegri favoured in the second half of the 2010/11 season (ironically leading to the end of Andrea Pirlo's career at Milan). For that to work, the creative players outside have to be mobile and athletic, as they become the driving force of the midfield while the Dutchman protects the defence and cleans up. In this scenario, Giacomo Bonaventura becomes a must-start in the midfield to give Milan the lateral quickness and incisive passing that they won't get from the central defensive midfield position. Keisuke Honda in a deeper, left-sided role is also an interesting option.
It's important to note that Milan had Thiago Silva in 2010-11, a defender with a near-unparalleled passing range for his position. Because of this Milan could afford to play a less creative player as the "regista", knowing Thiago could spread the play and act as a pseudo-regista. There is no such luxury in the current squad.
It was clear that the 4-2-3-1 didn't offer the same protection or give DJ-Monty enough space to operate, and the 4-3-3 appears to have been scrapped completely by Mihajlovic. If the 4-3-1-2 is the formation of choice (a decision that appears set in stone now), then Sinisia's decision becomes crucial to the success of the midfield and the identity of the squad.
Another interesting sub-plot is the issue of the captaincy. With Montolivo's performances requiring some major improvement, then his role as Milan's leader undoubtedly comes into question. How can Riccardo lead the team if he can't even get in the side? The emergence of (unsurprisingly) Nigel De Jong as a leader in training after signing his new deal in addition to his aggression aligning so perfectly with Mihajlovic's coaching style, the Dutchman could be the de-facto captain before Christmas. Handing the armband to a player like De Jong would go a long way in defining the new era with their new coach, as well as perhaps drawing a line under Montolivo's career at Milan.
Milan are hoping that the spark required at the base of the diamond can be forged in house. If so, the season could prove to have real value.