Real Madrid coach Jose Mourinho isn't going to divulge what he thinks of star player Cristiano Ronaldo's glum demeanour.

Ronaldo, the world's most expensive player, says he is "feeling sad" because of professional reasons the Portugal forward claims the Spanish giant is aware of.

Mourinho, speaking in Spanish sports daily AS, says "it's a theme in which I shouldn't nor can I comment on. I won't say anything about it."

The 27-year-old Ronaldo revealed his feelings after being asked why he had not celebrated scoring twice in a Madrid victory.

On Tuesday, Ronaldo issued a statement denying it's because of money while committing himself to the defending Spanish champions.

Ronaldo has scored 150 goals in 149 games for Madrid, including 59 in all competitions last season.