According to The Mirror, it is believed that Van der Vaart's relationship with Spurs, who signed the Dutchman from Real Madrid in the final hours of the 2010 window, has deteriorated to the point that the club are willing to sell.
The 28-year-old admitted his frustration after being omitted from Spurs' Europa League squad earlier this month.
He also sent a controversial text message to Netherlands teammate and Ajax midfielder Theo Janssen, who has confessed to being frustrated with his club.
"I was taken off in the Champions League against Olympique Lyon and I was really angry," he said. "The next moment I received a text message from Rafael [van der Vaart], who said he was wondering if I happened to have the same contract as he has at Spurs.
"I asked him what kind of contract that was? He answered: 'One which states that you are only allowed to play 70 minutes in each match.'"
The Dutchman's wife, a successful television presenter, also appears to be preparing for life in Milan after completing a photo shoot with a popular Italian magazine.