First Kaka wanted to leave
Ronaldo said he was upset with "people in the club" after scoring two goals to lead Madrid to a 3-0 win over Granada on Sunday.
The Portugal forward oddly chose not to celebrate his goals, remaining glum as his teammates and fans at the Santiago Bernabeu stadium erupted around him.
When asked why after the match, Ronaldo said: "I am sad and the club knows it, that's why I didn't celebrate the goals. The people in the club know why."
Ronaldo's comments have sparked rumours in the Spanish press that he is looking to leave Madrid.
The 27-year-old Ronaldo refused to elaborate on the reasons for his displeasure with the club that spent a record £80-million to secure him from Manchester United in 2009.
"I'm not going to say anything else, people know why," he said.
Ronaldo's outburst compounds the ongoing saga of what to do with club president Florentino Perez's other star signing, Brazil midfielder Kaka, who sought a transfer this offseason after being reduced to a bench player at best.
Yet while Kaka has been practically forgotten by Madrid coach Jose Mourinho, Ronaldo is the key player for the Spanish champions who have set winning the Champions League as their goal for this season.
Club record
Ronaldo's double on Sunday took his tally with Madrid to 150 goals in just over three seasons. He set a club record of 46 Spanish league goals last season, second only to Barcelona forward Lionel Messi's league record of 50.
Madrid striker Gonzalo Higuain said that he didn't know Ronaldo was unhappy.
"I see him as being fine. He scored two goals so I believe that he is happy," said Higuain. "My teammates and I all see him well."
Ronaldo, a former Ballon D'or, denied he was angry Barcelona's Andres Iniesta beat him for this year's players' award on Friday.
"It has nothing to do with it," he said. "Iniesta deserved it." – Sapa-AP