The defender is one of the club’s top earners on €4 million a season which the Berlusconi family see as excessive.
According to both Tuttosport and Sportmediaset the player could be sold to Monaco in the current transfer window.
Mexes would be reunited with former Roma boss Claudio Ranieri at Monaco with the club more than willing to meet his wage demands.
At the same time the Rossoneri have returned to the idea of signing current Liverpool full-back Aly Cissokho.
The Frenchman was a target of Milan in 2009 and now finds himself on a season-long loan from Valencia.
Milan will look to Adil Rami to replace Mexes in the first team instead of exploiting the pairs international experience.
Mexes has played 65 matches for Milan with his contract expiring in 2015.
Follow Louis Gibberd-Thomas on Twitter: @mercutio156