Modric was a signing demanded by coach Jose Mourinho.
"We have strengthened with Modric, the best footballer in his country, who upon finding out about our interest only wanted to sign for us," said Mourinho.
"This speaks of his commitment, a fundamental value in top competition. We have also signed Essien, a physical prodigy and excellent player. The reserve players Nacho, Morata and Jesús have convinced the coach and made themselves places in the squad."