“Today is a very special day for me. To form part of this club is an enormous achievement,” Illarramendi said after a handful of supporters had stopped chanting his name.
Illarramendi is from Mutriku, a coastal town in the Basque Country in northern Spain, and thanked Sociedad for the decade he spent growing up with the San Sebastian-based club.
“A few days ago I would have never imagined wearing any shirt other than that of Sociedad, but this is a once-in-a-lifetime opportunity,” he said. “Now I face a new challenge in my career. I assure you I will give it my all for these colors. I hope to keep growing with this club.”
Madrid paid Illarramendi’s buyout clause of 32 million euros ($42 million) and another 6 million euros ($8 million) in taxes on Friday to secure his release from the Basque club.
Illarramendi helped Sociedad earn a Champions League berth for this season and was part of Spain’s under-21 European champion side this summer.
He joins fellow under-21 teammates Francisco “Isco” Alarcon and Daniel Carvajal as Madrid’s reinforcements this offseason for new coach Carlo Ancelotti.
Illarramendi will now fight for playing time in Madrid’s star-studded squad to join former Sociedad standout Xabi Alonso in Ancelotti’s midfield.
Relatively unknown even in Spain, Illarramendi debuted for Sociedad’s first team in January 2011, the first of three appearances that season. He played 18 games in 2011-12 and started 34 last season.
Illarramendi provided a first line of defense in Sociedad’s midfield and his sure passing allowed it to deploy one of the league’s most attractive and effective attacks over the past two seasons. He has yet to score a goal in the first division.