Reports out of Spain suggest the Portuguese striker has told club president Florentino Perez that he wants to leave the Spanish champions.
It is widely reported that Ronaldo had a meeting on Saturday with Perez, director general Jose Angel Sanchez and his agent Jorge Mendes.
One Spanish radio station claimed that Ronaldo, who scored 46 league goals last season, cited a falling out between certain members of the team and did not feel as if the club valued him as a player.
Other reports suggest that the superstar – despite having three years remaining on his lucrative contract – is astounded he has not been offered a new deal.
Ronaldo played in Sunday night’s 3-0 demolition of Granada, scoring two goals in the process.
But the 27-year-old was substituted by Mourinho after a strong tackle from Granada’s Borja Gomez in the second half.
A worrying sign for Madrid was Ronaldo’s reluctance to celebrate either of his goals with any enthusiasm.
After the game the former Manchester United striker said: ‘I’m sad – when I don’t celebrate goals it’s because I’m not happy.
‘It’s a professional thing. Real Madrid know why I’m not happy.’
The Portugal captain refused to elaborate on the reason for his unhappiness, with Barcelona fans claiming he is just sulking because Inesta won player of the year over him despite Madrid winning the League, and him being the leading goal scorer.
Ronaldo, who began his career at Portuguese side Sporting Lisbon, left Manchester United for £82million in 2009 for the Bernabeu.