Kolarov joined City last month for £16million as part of another remarkable summer of team strengthening which has seen their Middle East owners plough more than £100m into the club.
And Mourinho, who joined Madrid after leading Inter Milan to a domestic and European treble last season, concedes even they can't compete.
"I understand that if someone wants to compete with them for a player it is very difficult, they are dominant in the market," he told Sky Sports News.
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"The player they say they want is the player they get. I was interested in Kolarov when I came here but I couldn't compete with them as they went to values that I couldn't.
"If they have the money they can do it, if they have the ambition to win the Premier League they can do it."
Mourinho believes this season's Barclays Premier League title race is between City, Manchester United and his old club Chelsea.
"I believe Chelsea, Man United and Man City, that's it," he added, before dismissing the chances of Liverpool. "It's very difficult for (new Liverpool manager) Roy Hodgson as over the last three years they have been getting worse, worse and worse. He needs time."
Mourinho also ruled out the possibility of signing Chelsea striker Didier Drogba and City's Emmanuel Adebayor. When asked about luring Adebayor to the Bernabeu, he said: "I think no chance.
"The historical dimension of Real Madrid and Manchester City you can't compare. But the economical dimension you can compare. I don't think, just one year after buying Emmanuel from Arsenal, he's the player to leave."
Drogba has also been linked with a reunion with Mourinho but the former Chelsea boss admitted: "Again, no chance."
Source: PA
Source: PA