The Switzerland international has been linked with a move away from Wolfsburg over the last couple of seasons, and it had been claimed that Arsenal and Chelsea wanted the left-back in the January transfer window.
Inter Milan and Paris Saint-Germain have also recently been linked with a move, but according to the 24-year-old's agent Fabio Parisi, a move to AC Milan is imminent.
"The negotiations are continuing, it's just Wolfsburg were tied up with the relegation playoffs," Parisi told Radio24. "The basic details are sorted out, we go forward and there's a very good chance it will go through.
"Everyone wants to finalise the move, the player wants to join Milan and Milan want to sign him. We just had to wait for the Wolfsburg result. I really think the move will be completed."
Milan, now under the ownership of Chinese group Rossoneri Sport Investment Lux, completed the signing of Mateo Musacchio from Villarreal on Tuesday, while head coach Vincenzo Montella has also penned a new contract with the Italian giants.