The Inter coach made a high-profile trip to Stamford Bridge to watch his former club defeat Fulham during the Christmas period and the 'Special One' gave an interview where he called Stamford Bridge his "home".
Since leaving the club in 2007, Mourinho has described the Blues as "my Chelsea", but Ancelotti said: "It's not true. It's not his team. It's the team of Roman Abramovich.
"It's not mine: it's Roman Abramovich's. Mourinho had the honour to train this club and I do too. This team is Roman Abramovich's team."
Avram Grant, Luiz Felipe Scolari and Guus Hiddink have taken charge since Mourinho's departure but Ancelotti is not concerned by the quick turnover of managers at Chelsea.
"Now is the time (for Chelsea to stick with a manager)," he said. "Pressure is normal when you do this job and I am not afraid of pressure. Here it is different - there is less pressure than the last year in Milan for me."