The Chelsea skipper was hauled off for the first time ever under the Portuguese boss, taken off at half-time, but 'the Special One' says that it was a purely tactical decision
The veteran centre-back was replaced by Kurt Zouma with the Blues a goal down and the champions went on to concede twice more as Chelsea made their worst start to a Premier League season in 17 years.
"John Terry [had no injury]. It was just a decision. I know that Kurt Zouma is the fastest defender Chelsea have," the Portuguese told Sky Sports.
"He is a player of my total trust. With me he was never substituted but, with other managers, he was not even playing. Some people thought his career was over. If anyone has the free mind to make this decision, I am the one because I'm the one who gave him the chance to be what he is: a fantastic player and captain.
"I left him out because, tactically, I had to make a change. Sometimes you are right and sometimes you are wrong but I think I was right. We controlled the counterattack completely afterwards. My decision was proven right.
"John is Chelsea captain, for sure, and a player with my entire confidence, for sure."
OPTA REVIEW All the stats from Manchester City 3-0 Chelsea
Mourinho was also of the opinion that Chelsea had been the better side in the second off at the Etihad Stadium and felt that both Fernandinho and Yaya Toure should have been sent off.
"The best team in the first half won the game," he remarked, "[but] the best team in the second half was Chelsea for sure. We had a difficult first half, we didn't create a lot and our goalkeeper made a few important saves.
"Second half, everything was different. If the 1-0 was a doubtful result at minute 70, 3-0 is completely fake. At 1-0 Chelsea were the best team for the whole second half.
"They make a change because they feel 1-0 is in danger and we concede a second goal. If 1-1 a different story, their team is in trouble."