Real will host Manchester City in their opening clash.
"It's normal to not have very high self-esteem when you don't start as well as you should, but tomorrow is a very good opportunity to win, and recuperate it 100%," said Khedira.
"It's very difficult to concentrate on a single competition. The Champions gets us going, but we could say that the Liga isn't enough and defending the Liga title motivates us. All competitions get me going and we have to have the same concentration for all of them."