The midfielder has joined from Real Sociedad.
"No, man, it's clear that Real Madrid is the best club in the world; they've proved it over the years. The president and his entire board of directors made a massive effort so that I can be here today and there's nothing more I can do than thank them as well as all the fans who gave me such an incredible welcome.
"The truth is that it changes my life a bit; I'm from a town of 5,000 people and moving to the capital won't be easy. It will be a pretty big change, but I'm not afraid. You have to face big changes in your life and it's an interesting challenge. So I hope that it all goes well for both me and the club."