Cole, who has been out of favour in recent weeks, raised eyebrows by attending his former club Arsenal's Christmas party just days before the sides were due to meet at the Emirates Stadium.
Mourinho played that down, but he gave Cole three day's notice that he will not be starting on Monday, with Spaniard Cesar Azpilicueta continuing in his position.
"Cesar Azpilicueta is fit," Mourinho told reporters. "I play Ivanovic right back, Azpilicueta left back. From the beginning Ashley Cole is not playing."
Azpilicueta has started Chelsea's last six Premier League matches, with Cole consigned to the bench.
He did start against Sunderland in the League Cup on Tuesday, but Chelsea's 2-1 extra-time defeat will have done little to boost his chances of a return.
After that match, Cole was pictured alongside Arsenal's players for their festive celebrations.
"I have an opinion I keep for myself," Mourinho said about Cole's social life. "It was a free day for them, I am not a father, I am a manager. I cannot control what they do when they are not with me.
"I don't want to comment. Not even to Ashley Cole, I gave my opinion because I don't have to. It was his free night, we don't train the next morning."
Mourinho drew attention to his team's lack of cutting edge.
While Chelsea sit third in the Premier League and are safely through to the knockout stages in the Champions League, they have suffered surprise results in recent weeks that have forced Mourinho on to the defensive.
While his mis-firing strikers have borne the brunt of the criticism, Mourinho believes defence might be the best form of attack if they are to convert their dominance into points on the board in the Premier League.
"Every match we are dominant. This is the responsibility from the players, when the team loses the ball for people to change their brains a little bit more," he said.
"To be a team that plays very good football and wins loads of matches is a more difficult step.
"That step is only possible when the team defends very well when they lose the ball."
(Reporting by Toby Davis; editing by xxx)
