MADRID (AP) -- Pressure is building on Real Madrid to come to terms with Cristiano Ronaldo on a contract extension, a deal the Portugal forward has carefully avoided mentioning since negotiations broke down last summer.
The Spanish press has been sending near-daily messages to Madrid President Florentino Perez along the lines of: "Renew Cristiano Ronaldo's contract now."
Ronaldo's importance to Madrid was glaringly obvious on Saturday when, with him serving a one-game suspension, Jose Mourinho's team was held to a humiliating 0-0 draw by bottom club Osasuna.
Madrid's offensive firepower of Karim Benzema, Gonzalo Higuain and Alvaro Morata -- supported by Angel Di Maria, Luka Modric and Xabi Alonso, and substitutes Mesut Oezil and Kaka -- seems unable to create match-winning opportunities without Ronaldo.
The Portugal forward has heightened the tension by playing his cards close to his chest.
"I want to see out my contract at Real Madrid. I'm very clear about that," Ronaldo said in an interview posted Monday on FIFA.com. "After that, well, I don't know what will happen in the future."
Sports newspapers Marca and As regularly publish polls which show that more than 70 percent of Madrid fans think Perez should renew Ronaldo's deal as soon as possible.
Adding to the pressure, Ronaldo has been the subject of media speculation that at least two European clubs -- Manchester City and Paris Saint-Germain -- are willing to make him the highest-paid player in the world.
Much of this speculation stems from Ronaldo's comment in September -- a month after contract negotiations failed to reach a conclusion -- that he was "sad" for professional reasons.
Some Madrid fans fear that Perez may be maneuvered into selling Ronaldo before his contract runs out in 2015 rather than accept agent Jorge Mendes' conditions.
Ronaldo earns €12 million ($16 million) net per season, though the total cost to Madrid has been €18 million because the club assumes some of the player's tax burden.
Mendes is known to have recommended a contract extension to Perez. Both sides are reported to view €15 million -- €1 million less than Barcelona's Lionel Messi makes -- as an acceptable fee. The big problem for Perez is that changes to tax laws elevate the total cost to Madrid to €30 million per year, a figure that Perez is wary of agreeing to.
One possible solution could be the sale of Kaka, financial newspaper El Economista said Monday.
Since his arrival at Madrid in 2009, Kaka's performance has fallen to levels that have caused Mourinho serious concern. Year after year, the Brazilian has been a disappointment to fans.
In 2010 Kaka was hampered by physical problems and the following year his poor games against Barcelona made matters worse. In 2012 he played a terrible match against Bayern Munich in the Champions League semifinal, including missing a penalty. Things got worse Saturday when Kaka was sent off after two yellow cards in just over 15 minutes after coming on as a substitute in the second half.
El Economista says Madrid will accept a free transfer for the Brazilian if the club doesn't have to pay him the same salary as Ronaldo, which it is currently committed to honoring.
Kaka's release could clear the way for a new deal with Ronaldo.
And that could help achieve Perez's most cherished ambition -- winning a 10th European title.
With the domestic league almost certainly beyond reach, 18 points behind Barcelona after 19 matches, Madrid longs to rekindle European success last tasted in 2002.
"Every Madrid fan wants that 10th European Cup," Ronaldo said. "We're more than aware of that."