The France international only moved to White Hart Lane in the summer from Newcastle United for a fee of £30m.
However, since making the switch, the 27-year-old has struggled to find his feet and speculation has grown that he could be shown the door already.
Milan, according to Calciomercato, have been alerted to this and they are now working on a deal for Sissoko.
The Italian club are ready to invest heavily this summer when it is hoped Chinese consortium Sino Europe Sports will have completed their takeover.
A number of targets are already being drawn up by Milan, with Sissoko seemingly high on their summer shopping list.