Sanches starred for Portugal during their Euro 2016 triumph last summer, before joining Bayern in a big-money move from Benfica, rejecting the chance to join Manchester United in the process.
Ancelotti has said that "there is also a chance" of Sanches staying with Bayern this summer, but the Italian has hinted that the teenager will depart.
"At this time, he's training with us. We have to make a decision. A move could be a possibility but there is also a chance he could stay with us for the season," Ancelotti told reporters.
Man United are also believed to be considering a summer move for the young midfielder.