Ahead of this week's return to Stamford Bridge with Benfica in the Champions League, Mourinho discussed his former club.
He said: “Chelsea. (Roman) Abramovich’s Chelsea, my Chelsea, the Chelsea we built and lasted for many years was a winning club. It was winning everything with me and then with (Carlo) Ancelotti, with (Antonio) Conte and with (Thomas) Tuchel.
“Chelsea was a winning machine. Every season, Chelsea was winning.
“Then there was a big change with crazy investment and a period of a few years where it looked like they lost direction, with too many players, too many millions, accumulation of players and a team without a clear philosophy.”
He continued, “For a couple of years, it was hard. For one that loves the club, it was hard."
However, Mourinho says Chelsea can be proud of their European success last season.
He added, “Even the Conference League is a fantastic competition for a team like that to win. It gives you that first cup and the philosophy and the culture of the club for winning.”