Asier Illarramendi signs 6-year contract to become 1 of Real Madrid's most expensive transfers

Midfielder Asier Illarramendi is now Real Madrid's sixth most expensive transfer ever after signing a six-year contract with the Spanish powerhouse.

Madrid paid Illarramendi's buyout clause of $42 million and another $8 million in taxes Friday to secure his release from Real Sociedad, making the relatively unknown player the club's most costly Spanish acquisition.

Only Cristiano Ronaldo, Zinedine Zidane, Kaka, Luis Figo and Ronaldo have cost Madrid more. And they were already stars before arriving in the Spanish capital, while Illarramendi has yet to score a goal in Spain's top league.

The 23-year-old Basque completed his move from Sociedad on Saturday after passing a medical exam with Madrid's team doctors and signing the deal with Madrid club President Florentino Perez.