The Spanish giants dropped their first points of the season on Sunday in a 2-1 defeat at Sevilla.
Several Real players were missing, including Cristiano Ronaldo.
“He is an important player,” said the Madrid coach. “But you build a team for when there are absentees.”
He added: “Two errors cost us the game and at the end we had the chance to equalise.
“Sevilla are going through a great time and they are the rightful winners.”
“You can’t go away happy when you lose,” he added. “We were at fault for both goals.
“I believe the game was lost because of defensive errors. I’m worried that they got two headers against us from players that are a lot shorter.”
