Vincenzo Montella has been given money to spend by Milan's new owners, having already signed over €100m worth of players, including Andre Silva, Ricardo Rodriguez and Franck Kessie during the summer transfer window.
The new Milan manager has Bonucci as his next target, but Goal understands that Juventus are holding out for more than the €30m being offered.
Milan had initially been in contact with Bonucci's agent Alessandro Lucci, who also represents Milan's Andrea Bertolacci, to assess the possibility of a switch from Juventus Stadium to the San Siro. Following these initial meetings, talks have opened between Milan sporting director Marco Fassone and Juventus CEO Beppe Marotta.
A possibility to help push through the transfer would be the inclusion of Mattia De Sciglio in the deal. The full-back has been linked with a move to China, but Milan could use the 24-year-old as an addition to sweeten the deal.
Bonucci has previously played at the San Siro with Inter Milan but left the club in 2009 after failing to break into the first team. He then spent one season at Bari before joining Juventus, where he has played over 300 games and won six Serie A titles, three Coppas Italia and three Supercoppas Italiana.