Questions have been asked about the midfielder's love for the capital outfit after a past interview emerged in which he labelled Madrid "an arrogant club"."
Isco joins a Madrid midfield which already boasts an embarrassment of riches, such as Xabi Alonso, Mesut Ozil, Luka Modric, Angel Di Maria, Kaka and Sami Khedira, and he admits it will be hard to cement a regular place in the first team.
"Winning a place in the best team in the world is very difficult and match time here doesn't come for free, but I hope with hard work I will win my place my team," he said.
"There needs to be a lot of competition in every great team, it's a good sign, and I've come here to find my way into the team and win many things."
Isco will wear the number 23 shirt formerly worn by David Beckham, but he said he chose the number "because it's the day of my brother's birthday".