"It was very difficult for us. You just have to look at the League table," the Bilbao boss told reporters.
"When one team is moving further away from the rest, it's clear that they are better. It's no coincidence they are at the top of the table.
"Atleti are very, very strong. I thought we started the game well, but after that they were better than us. We were well beaten."
Bilbao currently sit fifth in the league table, while Atletico are second.