Oihan Sancet had Athletic ahead before Getafe equalised via Chrisantus Uche.
"It wasn't a good match for us. They were strong in the duels. We didn't play at the right pace," Valverde said.
"We were lucky enough to score the first goal in the first half, but when you don't have control of the game, they can trouble you with any long ball. When we tried to react, it was too late.
"You have to give Getafe credit. They're a complicated team, difficult to get past. They're very strong in any situation.
"More than looking at our opponents, we have to look at ourselves, at what we didn't do well to win. We have to do things better, the way we are used to doing them. LaLiga has started now and we have to be clear about that."
On goalkeeper Alex Padilla on debut, Valverde added: "He had a lot of responsibility, he's Athletic's goalkeeper and we know what that means. He responded brilliantly to his first start at San Mamés, he prevented a goal we didn't want to concede and he was very composed."