Only months after leading Real Madrid to La Liga title, Portuguese star Cristiano Ronaldo says he is "unhappy" at the Spanish club, claiming his refusal to celebrate the two goals he scored in the Sunday’s 3-0 La Liga victory over Granada was "a professional thing."

In what appeared to be a swipe at Real Madrid president Florentino Perez, Ronaldo said, “I’m sad -- when I don’t celebrate goals it’s because I’m not happy. It’s a professional thing. Real Madrid knows why I’m not happy.”

Alfredo Relano, editor of Spanish newspaper AS, says the issue is money. "A while ago he was talking about a contract for life. But the price of a superstar has gone up after all the goals he has scored and after all Madrid have won."

Problem is, changes in Spanish tax laws abolishing tax breaks for high-paid foreign workers mean Real Madrid will find it very difficult to pay Ronaldo what he wants when his contract expires in June 2015. In the meantime, don't expect to see Ronaldo moving elsewhere. There is a $1.25 billion -- that's right, $1.25 billion -- buy-out clause in his contract.