Though an early-season torrent of goals has dried up for the Neroverdi of late, Roberto De Zerbi's side have continued to keep company with Calcio's established big boys.
Perhaps inevitably, given the ferocious pace of their start to the 2020-21 season, Milan have started to stutter as they head towards the mid-season break within touching distance of being crowned Italy's 'winter champions'.
City rivals Inter have started to close a once yawning gap between the clubs, as the Rossoneri's lead at the Serie A summit has been trimmed to just a single point.
The relentless winning form of Antonio Conte's well-drilled team has of course been a major factor in that narrowing, but Milan have also been held to successive 2-2 draws by mid-table Parma and struggling Genoa.
Against Parma last week, they relied on flying full-back Theo Hernandez's brace to bail them out after falling two goals behind. Again, on Wednesday, former Milan striker Mattia Destro twice breached their defence before rookie defender Pierre Kalulu proved an unlikely Rossoneri saviour - with goalkeeper Gianluigi Donnarumma then needing to pull off a spectacular save to secure a point for his side.
Nonetheless, Milan remain unbeaten in the league, even if they have begun to feel the absence - in terms of both goals and leadership - of injured superstar Zlatan Ibrahimovic.
Each of the Rossoneri's last nine goals in Serie A have been netted by midfielders or defenders – the last Milan striker to have scored in the league was Ibrahimovic, versus Napoli on November 22.
Makeshift cover striker Ante Rebic has offered endeavour but little genuine cutting edge and Stefano Pioli's squad is particularly light in that department, even after the recent return of Rafael Leao.
With reports emerging that Ibrahimovic will struggle to recover in time for the trip to Sassuolo this weekend and could possibly sit out the rest of 2020, other members of their talented supporting cast must step up to centre stage if Milan are to continue their positive performance on the road - before the Genoa game they had won every away encounter this term.
Sassuolo coach Roberto De Zerbi certainly appreciated the return of two of his chief attacking threats in midweek, as goals have become harder to come by for his forward-thinking side in recent weeks.
Italy international Francesco Caputo and experienced French striker Gregoire Defrel made their long-awaited returns in Florence, as the Neroverdi were held to a 1-1 draw by Cesare Prandelli's reshuffled Fiorentina team.
That leaves the Emilian side occupying fifth place in the Serie A standings, level with Napoli on 23 points, ahead of Milan's visit to the Mapei Stadium.
Sassuolo have lost six of their last eight games against the Rossoneri, failing to score in four of their last seven meetings, so will have recent history against them on Sunday.
Not only that, but they have picked up only two points in their last nine league matches against teams starting top of the table and have won just two home games so far - the fewest in the top seven. Therefore, a victory for the home side would be something of a surprise, even for a team that continues to defy the odds.
Sassuolo Serie A form: DWLDWD
AC Milan Serie A form: DWWWDD
AC Milan form (all competitions): WWWWDD
Zlatan Ibrahimovic was expected back this weekend but Milan's talismanic centre-forward suffered a calf strain during training and could now be out for up to a month - potentially missing out on the seismic clash against Juventus on January 6. His makeshift cover, Ante Rebic, trained separately during the week and has since been omitted due to a foot injury, so Rafael Leao may move up front.
Emil Roback - a 17-year-old forward from the Milan Primavera, who arrived from Hammarby this summer - has been included in the squad for the first time and joins Daniel Maldini as striking back-up on the bench.
Another integral attacking threat from left-back in Stefano Pioli's first-choice XI, Theo Hernandez sat out the Genoa game with muscle fatigue but should return on Sunday. However, Simon Kjaer, midfielder Ismael Bennacer and Matteo Gabbia are all out.
Midweek goalscorer Pierre Kalulu should keep a centre-back starting spot in Kjaer's absence, while Sandro Tonali covers Bennacer.
To the delight of Roberto De Zerbi, defender Vlad Chiriches and forwards Francesco Caputo and Gregoire Defrel returned to the fray in midweek and could all be involved against Milan.
Sassuolo possible starting lineup:
Consigli; Toljan, Chiriches, Ferrari, Rogerio; Obiang, Bourabia; Berardi, Djuricic, Boga; Caputo
AC Milan possible starting lineup:
Donnarumma; Calabria, Kalulu, Romagnoli, Hernandez; Kessie, Tonali; Saelemaekers, Calhanoglu, Hauge; Leao
We say: Sassuolo 1-1 AC Milan
Though the wheels are hardly falling off the Milan wagon after back-to-back draws, momentum has definitely been lost in the injury-hit Rossoneri camp.
It is hardly ideal, then, that Sunday's opponents are returning to full strength and could well prove too difficult a nut to crack for Stefano Pioli's side, given 'King' Zlatan's prolonged absence.