Los Blancos lost 1-0 to Sevilla to leave them eight points behind perennial rivals Barcelona – and with a high-profile Champions League tie against Manchester City just two days away.
“We have only really played well in the Spanish Super Cup [where they beat Barcelona], nowhere else. I am worried that in this moment I don't have a team,” Mourinho said.
“There are very few heads who are committed and concentrated. When you don't have people who are committed, it's tough. But I am the coach, and if there are people who aren't committed it is my fault.”
He added: “For Sevilla, every ball was the last one in their life. They played with perfect aggression in everything. They wanted to play quickly, move the ball quickly. My team did it against Barcelona and haven't done it in any other game.”