AC Milan managers have been doing some great business in the previous transfer market windows by signing interesting profiles on affordable deals.
There are a number of players who can further solidify the squad of Stefano Pioli and keep the team competitive. These are players who can add quality and flexible tactical options for the coaching staff.

AC Milan boss can use an addition in the attack, even in January's coming mercato given the conditions of Olivier Giroud and Zlatan Ibrahimovic, respectively aged 35 and 40. Pietro Pellegri does not offer much yet and that is why a promising low-cost talent can be a solution, such as Luka Jovic:
Luka Jovic - Real Madrid

The Serbian striker, Luka Jovic, who made a sensational summer move to Spanish giants Real Madrid in 2019 for a fee over 60 million euros has seen his pricetag go down to around 20 million euros, as per Transfermarkt. The centre-forward is still struggling to find his form, even after an underwhelming loan spell with Eintracht Frankfurt. AC Milan could choose to go after him. Stefano Pioli has been good with taking care of unleashed talents such as Theo Hernandez and Brahim Diaz who struggled to find minutes at Los Blancos. The abilities and skills are undeniable for Jovic, and a loan deal in January might be possible.
Angelo Fulgini - Angers SCO

AC Milan management always keep an eye on players in Ligue 1. They can add one more French-speaking talent to their squad. Fulgini is 25 years old and has a contract with his club, Angers, valid until June 2023. He is versatile because he can occupy different roles in the midfield such as the central midfielder, playmaker and right winger. He is quick, a good dribbler with a great vision in the pitch. He could be a low-cost solution and suitable to strengthen the bench.
Robin Le Normand - Real Sociedad

Carrying on with French talents, but this time we move to La Liga. In Spain, a really interesting name is coming up in the radar and that is: Robin Le Normand of Real Sociedad. He is 24 years old, a centre-back standing at 187 cm with great physique. He is quick, has precise tackles in his arsenal and does not shy away from physical confrontations in the pitch. He reads the game well. The defender has been making progress and was already linked with Premier League move as Manchester United were keeping an eye on him last year. Eventually, they opted to sign World-class name in Raphael Varane, from Real Madrid in the last summer. AC Milan could swoop in for the defender with the usual loan and option to buy, especially if Alessio Romagnoli leaves on a free.
Corentin Tolisso - Bayern Munich

With Franck Kessié's contract renewal getting more complicated each day, Paolo Maldini and Frederic Massara can find a good opportunity in Corentin Tolisso. The French central midfielder has been an outcast at Bayern. However, he has many more years left in him. He is 27 years old and he can still reach an important level in his career if he makes a move away from Bayern. Champions League and World Cup trophies to his name, Tolisso can start looking for a new challenging adventure and AC Milan can be the right environment for him.
Wilfried Singo - Torino

Franck Kessié's compatriot, Wilfried Singo, should be on AC Milan's shortlist. He is 20 years old and ha a valid contract until 2023 with Torino but Urbano Cairo holds an option to extend the deal by 1 year. The young talent is standing at 190 cm but he is fast. He plays as a right-back mainly (edit) . However, he may also be deployed as a centre-back which is a position he occupied a few years ago in Torino's Primavera ranks. Alessandro Florenzi has been underwhelming in the few times he has appeared and if the Italian right-back (who is currently injured) continues like this, the Rossoneri may turn to Torino's wonderkid.
AC Milan has options in the mercato...
Thanks to a competent coaching staff, management and scouting department, the Rossoneri club is well-equipped to go after interesting players who are available in the mercato. Il Diavolo executives have done great business like signing Fikayo Tomori, Alexis Saelemaekers, Theo Hernandez and others. Maldini and Massara must continue with this philosophy. If the club, however, manages to pass the group stage in the Champions League, we can perhaps expect a war chest ready to be spent in January in order to land an important name or two.