Sosa, who arrived last summer from Turkish side Besiktas for €7.5million, could already be on his way out of Milan.
Sosa (32) played an total of 19 games for the Rossoneri but has failed to impress during the 16/17 season and has quickly been deemed surplus to requirement by Vincenzo Montella.
The Rossoneri already have a wealth of midfield options, meaning Sosa is far enough down the pecking order to be considered dispensable.
Sky Sports is reporting that Trabzonspor, another Turkish side, has agreed a three-year contract with the Argentine midfielder and could make a new bid for the player in the upcoming hours.
Sosa, who is valued around €5million, is part of the group of players, alongside Gabriel Paletta, Gustavo Gomez and M’baye Niang, AC Milan are trying to offload since the beginning of the summer.
This is in order to compensate for the 11 players who already joined Montella’s squad, plus the possibility for new arrivals may depend on the wage budget being cleared up.