The Portuguese coach is under pressure to succeed, as The Blues currently sit in fifth place in the Premier League and are facing Champions League elimination.
Ancelotti, who was sacked at Stamford Bridge a year after winning a domestic double, feels that Villas Boas should be backed in the long run.
“I think that the problem at Chelsea is that they have tried to change something, to have a younger team, to give more opportunity to the younger players, to play, to try to give less matches to the most important players – Frank Lampard, Ashley Cole, John Terry,” he told Mirror Football.
“But I think that this change needs time because it is very difficult to substitute players like Lampard, like Ashley Cole, like John Terry, because they are Chelsea’s important players.
“Villas-Boas is a good coach, because he did a very good job at Porto. It’s the philosophy of the club. They have tried to change something. This change needs time,” he admitted.
By Gareth McKnight