With Francesco Acerbi and Cristian Zapata failing to impress at San Siro, the Rossoneri are still searching for a proper replacement for Thiago Silva.
La Gazzetta dello Sport understands that Feyenoord stopper Bruno Martins Indi has moved to the top of their hit list.
Milan sporting director Ariedo Braida watched the player in action as Netherlands beat Romania 4-1, which proves the Serie A side are very interested.
The 20-year-old defender became a first team regular at Feyenoord when he was just 18, while he has also been given a chance to impress at international level.
Martins Indi started all four 2014 World Cup qualifiers for Netherlands and even managed to score two very important goals.
As far as his club career is concerned, the youngster has scored 3 goals in 52 Eredivisie appearances for Feyenoord.