Ronaldo will play against Sevilla today a fortnight after claiming he was "sad" about his situation at Real.
Mourinho said: "I'm a football coach and at this moment the only thing I'm concerned about is that my team still haven't played well.
"If Cristiano's sad and he plays like he plays, then that's perfect for me.
"Cristiano works at 100%, plays at 100%. At times he does better and other times worse. He cannot be the match-winner in every game but he's always a team player, who in every training session and in terms of discipline is exemplary.
"I don't have to worry about things that for me are supplementary and not fundamental."
Mourinho also urged the media and public to judge Ronaldo on his performances and not speculate on other issues.
"I think you (media) have had 15 days to speculate because there hasn't been any football or special international matches.
"Now Cristiano needs peace and tranquility to play football, which is what he knows and likes most.
"You, the Bernabeu and the public, we must evaluate his performances on the pitch and nothing more.
"If tomorrow in the 75th or 80th minute he has played a horrible match, or he's tired, then he'll be taken off and someone else will come on, that's how it is."