Eibar were comfortably beaten 3-0 by Real.
The coach remarked: "The beginning has not been good. In addition we are missing many important players. The spirit is improving, I hope to see this during the next games. Spirit is always important for me. The last two games have improved. The players look better.
"Getting something out of here is tricky. They always make 5-6 chances, even if they do not play well."
Asked about Real striker Karim Benzema, Mendilibar added: "In my opinion Benzema is the best nine in the world. For qualities at least. He brings a lot. We all have better or worse moments."