While top spot in Group E is already decided, with Chelsea set to finish first, the Rossoneri must avoid defeat or face being leapfrogged by their visitors into second place.
Match preview
After a run of four straight Serie A wins, Milan travelled to Croatia last week, where they were in dire need of a positive result - having posted only one win from their first four Champions League fixtures.
Narrowly ahead following the first half - after breaking the deadlock through stand-in centre-back Matteo Gabbia - the Scudetto holders went up through the gears in the second, and strikes from Rafael Leao and Olivier Giroud, plus a calamitous own goal by the hosts, put the gloss on a 4-0 win over Dinamo Zagreb.
Milan therefore sat second in both Group E and the Italian top flight, but after making several changes to his lineup to face Torino at the weekend, coach Stefano Pioli finally came unstuck: his side lost for both the first time in 18 Serie A away matches and just the second in the league this season.
That saw the injury-hit Rossoneri slip to third, and six points adrift of free-scoring Napoli, but at least victory at Stadion Maksimir leaves them in charge of their own destiny in Europe.
Now, Pioli's men require only a draw against closest rivals Salzburg to seal second spot in Group E, which puts them tantalisingly close to a place in the last 16 for the first time in nine long years. Whatever happens, continental football is already assured for 2023: Milan can no longer finish fourth.
They are, ideally, seeking to register consecutive Champions League wins for the first time since October 2011, which would secure the name of the seven-time European champions in the last-16 draw on Monday.
Precedent is certainly on their side when it comes to Italo-Austrian duels from past years, as Milan have lost just one of 12 meetings with teams from the neighbouring nation; going unbeaten in each of their last eight.
Indeed, no Austrian club has won a UEFA-sanctioned game at San Siro in 12 previous attempts, with Salzburg's only other Champions League away fixture against Milan resulting in a 3-0 defeat back in the Rossoneri's 1994 heyday.
This year, though, Die Roten Bullen are aiming to reach the knockout stages for the second successive season, having failed to progress past the group phase in any of their three previous campaigns.
As it is a simple case of 'win or bust' on Wednesday, Matthias Jaissle's side intend to throw everything at it, having talked of preparing for "a final" at the iconic Stadio Giuseppe Meazza.
The perennial Austrian champions were left in such a parlous position by losing 2-1 at Chelsea last time out, as an entertaining encounter slipped away from them due to a Kai Havertz winner midway through the second half; Junior Adamu's fine equaliser being ultimately rendered meaningless.
Salzburg had remained unbeaten in Group E until that point, and without defeat in 16 matches all told, but they did bounce back with a Bundesliga win over Hartberg on Saturday - Swiss striker Noah Okafor netting the only goal.
Twenty-two-year-old Okafor is just one of several players aged under 23 to have scored for the club in the Champions League under Jaissle - in fact, all of their last 15 strikes were provided by such young guns. Furthermore, Salzburg have fielded the youngest starting XI on average in this year's group stage: just 22 years and 279 days.
They will hope, then, that fearlessness can see them create history at San Siro and sneak through to the last-16 with a famous victory. However, there still looms the threat of finishing fourth and entirely empty-handed if they lose and Dinamo win.
AC Milan Champions League form:
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W
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W
AC Milan form (all competitions):
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L
W
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L
Red Bull Salzburg Champions League form:
D
D
W
D
L
Red Bull Salzburg form (all competitions):
L
D
D
W
D
L
Team News
Stefano Pioli, who this week signed a new contract with Milan set to run until 2025, has recently had an unsettled XI due to injury and - particularly at the weekend - his need to rotate some players.
Such a policy did not pan out too well in Turin, so Ismael Bennacer and Olivier Giroud should come back in to the side; Tommaso Pobega and Divock Origi making way. Last week, Giroud scored his 20th Champions League goal, aged 36 years and 25 days; thereby becoming the oldest player in history to do so.
At the back, meanwhile, Fikayo Tomori returns after serving a suspension in Zagreb, and the England defender should join up with either Matteo Gabbia or the vastly experienced Simon Kjaer at the heart of the hosts' back four.
Still on the injury list are full-backs Davide Calabria (thigh) and Alessandro Florenzi (thigh), plus Belgian winger Alexis Saelemaekers (knee). Mike Maignan and Zlatan Ibrahimovic remain sidelined too.
Salzburg's concerns in that department include last week's goalscorer Junior Adamu and Oumar Solet, both of whom are struggling with thigh problems and may not be fit in time.
Fernando and Nicolas Capaldo will be unavailable to Mattias Jaissle, who could start with Noah Okafor and Slovenian starlet Benjamin Sesko in tandem up front - depending on Adamu's readiness.
Max Wober will battle it out with 36-year-old Roten Bullen captain Andreas Ulmer for selection at left-back, though the former is also able to shift into the middle if required.
AC Milan possible starting lineup:
Tatarusanu; Kalulu, Tomori, Kjaer, Hernandez; Tonali, Bennacer; Rebic, Diaz, Leao; Giroud
Red Bull Salzburg possible starting lineup:
Kohn; Dedic, Pavlovic, Wober, Ulmer; Gourna-Douath; Seiwald, Sucic, Kjaergaard; Okafor, Sesko