While Milan finally got off the mark with a win in midweek, their Rossoblu rivals remain pointless in Europe's top club competition - and they have fared little better in Serie A.
Match preview
Having lost their first two matches, Milan revived an ailing Champions League campaign on Tuesday evening, when they saw off 10-man Club Brugge at San Siro.
The seven-time European champions went in front when Christian Pulisic scored direct from a corner, before their visitors had a player sent off and then equalised against the odds; two substitutes saved the Rossoneri's blushes, with Noah Okafor and Samu Chukwueze both setting up clinical strikes from Tijjani Reijnders.
It was a case of swift redemption for Reijnders, who had been dismissed during the first half of last week's backs-to-the-wall league win over Udinese, when Milan clung onto a lead provided by Chukwueze's early goal despite playing over an hour with 10 men.
Since the beginning of last season, the Lombardy club have received more red cards than any other team throughout Europe's top five leagues (11, with three so far this term), leaving head coach Paulo Fonseca with a discipline issue to resolve.
Milan may have won just one of their first four away games in Serie A and begin the weekend five points adrift of top spot, but they will now meet their favourite opponents.
The Rossoneri are unbeaten in 17 league games against Bologna, winning 13 times since their last loss in January 2016 - their longest active streak without defeat versus any top-flight team.
Furthermore, Bologna have not won any of their last 18 contests with Milan at the Dall'Ara, and that dismal run dates all the way back to 2002.
The Emilian side will be desperate to taste victory on this occasion, as following their 2-2 draw with Genoa last week - in which they let a two-goal lead slip during the last 20 minutes - they have now drawn six of their first eight Serie A fixtures.
In fact, Vincenzo Italiano's side would set a new club record with one more this weekend, when they hope to move up from a modest 13th place in the standings - last term's superb top-five finish already seems a distant memory.
Though they have only suffered only two losses since the end of August - both at the hands of Premier League opponents - and could now extend their undefeated streak in domestic football to seven matches, Bologna have persistently failed to turn one point into three.
Meanwhile, Italiano and co still await the first goal and first point of their debut Champions League campaign, after Tuesday's 2-0 defeat to Aston Villa saw them become the first club not to score in any of their opening three fixtures since 2013.
All of which leaves a lot riding on the Rossoblu's trip to San Siro, plus two upcoming games against Serie A strugglers Cagliari and Lecce.
Bologna Serie A form:
D
D
W
D
D
D
Bologna form (all competitions):
W
D
L
D
D
L
AC Milan Serie A form:
D
W
W
W
L
W
AC Milan form (all competitions):
W
W
L
L
W
W
Team News
Milan will be without French full-back Theo Hernandez and Dutch midfield dynamo Tijjani Reijnders, both of whom must serve suspensions, and the latter's absence could open up a chance for either Samu Chukwueze or Noah Okafor to start on Saturday evening.
Alvaro Morata should continue to lead the visitors' attack, and Bologna are one of two teams - along with Real Sociedad - against which he has been involved in the most league goals (seven - four of his own and three assists).
The Spain striker is ably supported by Christian Pulisic, who has played a part in at least one goal during each of his last seven Serie A appearances. Only one Milan player has posted a longer run over the past two decades: Zlatan Ibrahimovic managed a streak of 10 nearly 14 years ago.
Ismael Bennacer and Alessandro Florenzi are the Rossoneri's long-term absentees, but both Davide Calabria and Tammy Abraham could return to the bench.
Meanwhile, Bologna will be missing Nicolo Cambiaghi, Oussama El Azzouzi, Martin Erlic and Lewis Ferguson, while Swiss midfielder Michel Aebischer is a major doubt due to an adductor problem.
Vincenzo Italiano will again weigh up who gets the nod up front: teenage striker Santiago Castro vies with Thijs Dallinga, who was handed a rare start at Villa Park.
Bologna possible starting lineup:
Skorupski; Posch, Beukema, Casale, Miranda; Freuler, Moro; Orsolini, Fabbian, Ndoye; Castro
AC Milan possible starting lineup:
Maignan; Emerson, Tomori, Gabbia, Terracciano; Fofana, Loftus-Cheek; Chukwueze, Pulisic, Leao; Morata
We say: Bologna 1-2 AC Milan
Bologna have dropped eight points from winning positions in Serie A this season, and their confidence must be low after slipping up last week, then being beaten in Birmingham.