Ronaldo and Kaka joined from Manchester United and AC Milan respectively as Real president Florentino Perez spent big to help Los Merengues compete with arch-rivals Barcelona for the league title.

They scored 10 goals between them after 15 Primera Liga games.

"Ronaldo's attacking moves make the difference. His speed and ability to score benefit us," Alonso said in an interview with Spanish daily Marca.

"Kaka? From his position, he can make this team play even better.

"I think we can combine our own style of football to create a more destabilizing effect compared to Barcelona."

Real entered the league's winter break in second place with 37 points, two behind leaders and defending champions Barcelona.