Angel di Maria admits Real Madrid's two German players will be crucial in their Champions League semifinal against Borussia Dortmund.

Sami Khedira and Mesut Ozil have been in impressive form since the New Year.

"They have improved tremendously and have developed in every way. Khedira and Ozil are both playing as well as ever. Sami is doing really well and the coach really sees that. Mesut is also getting a lot of assists and both of them are important for us," said Di Maria.