The Ajax midfielder has been linked with a number of clubs, including Manchester United, Manchester City and Bayern Munich.
However, it now appears that Milan are trying to steal a march on their European rivals by making contact with the player's representative.
"AC Milan is an interesting solution and a way forward," said agent Martin Schoots.
"I don't know if he's ready for such an important club, but he certainly has the qualities to do well in all leagues.
"At this time, however, his task is to grow at Ajax."
It has been reported that Ajax will demand at least £20m before they consider allowing the Danish international to leave the club.