Fabio Cannavaro doubts whether Kaka and Cristiano Ronaldo will solve the "internal problems" he believes exist at Real.

And he is not convinced acquiring two world stars will help the club close the gap on treble winners Barcelona.

"The club is going to have to do more because these players will not solve the internal problems," said Cannavaro, who is currently with the Italy squad in South Africa building up to the Confederations Cup.

"The most important thing for the team is to achieve a group mentality."

Madrid have come under fire for spending 166 million euros on two players in the current economic climate, but Cannavaro is not surprised they have targeted the best.

"They are incredible figures, astronomical ones, especially in a world crisis as we are experiencing now," he said. "But those figures reflect the club culture of always being accustomed to being the best."

And Cannavaro expects Real Madrid president Florentino Perez's shopping spree to continue.

"I think Madrid need five signings," he said. "Most of them in attack, as that is Real Madrid's playing mentality."

Watch Barcelona president Juan Laporta response to Real Madrid's recent record-breaking signings