Mario Balotelli: Banned for three games.
The Rossoneri have had a poor start to the campaign, taking just four points from their opening four fixtures.
They come into the game on the back of a 1-2 defeat at the hands of Napoli, Rafa Benitez's side recording their first victory at San Siro in 27 years.
According to Transfermarkt, the home side had 16 shots on goal but failed to find the back of the net until Mario Balotelli scored in the 90th minute, the forward having had a penalty saved by Pepe Reina on the hour mark.
Milan right-back Ignazio Abate told the club's official website that his side are lacking a competitive edge:
We have four points and a lot of work to do. We have to win, for us, for the league table and that starts on Wednesday. We have to find more balance with the tactics that we're using in the new formation. Compared to the start of last season, we have more identity but maybe we're missing a bit of competitiveness. I think we have some work to do with our self-confidence as well as this team really has quality, we just have to be more cynical.
Currently 11th in the table, Milan were in a similar predicament at this stage last term. With just three points from their first four games, 2012/13 was Milan's worst-ever start to a Serie A season.
Incidentally, their solo victory came against Bologna at the Renato Dall'Ara Stadium, Giampaolo Pazzini with a hat-trick for the visitors in a 1-3 win.
Milan will be without the injured Pazzini this time around. Their injury woes will also see Stephan El Shaarawy, Kaka, Riccardo Montolivo, Mattia De Sciglio, Matias Silvestre and Daniele Bonera all sidelined.
To add to Massimiliano Allegri's concerns, Balotelli has been banned for three games after using "intimidating and insulting words" toward the referee in Sunday's game against Napoli, as seen on the BBC Sport website.
Milan, largely reliant on Balotelli in attack, will have to dig deep to try and engineer their first away win of 2013/14.
Even though he managed to steer them toward a third-place finish and qualification for the Champions League last season, Allegri's position is looking more and more precarious.
After the weekend's loss, the Milan boss maintains that his side need to keep their cool ahead of facing Bologna. He was quoted on the club's official website, as saying, "We really have to do well in the next two matches. After the matches we need to stay calm even if angry and on one [SIC] knows what’s in another person's mind. Hysteria doesn't help anyone."
The hosts will also be without several players; defender Cesare Natali has been banned for three games after picking up a red card against Torino on Sunday. Bologna's Panagiotis Kone also has a one-match ban for accumulating four consecutive yellow cards.
Going into Wednesday night's game, Bologna sit in 16th, so far Stefano Pioli's side have played four, drawn two and lost two.
Bologna have not beaten AC Milan since the 2008/09 season, when they defeated them 1-2 at San Siro.
Pioli has just two players missing through injury; centre-back Nicolo Cherubin and midfielder Rene Krhin.
Date: Wednesday, September 25
Time: 19:45 BST/14:45 ET/20:45pm CET
Stream: beIN Sport Play (for beIN Sport subscribers), Bet 365 (requires registration)
Television: beIn Sport Play. Repeat broadcasts on beIN Sport en Espanyol, Setanta Ireland