Koke scored the only goal of the game eight minutes in.
"We only had the league on our minds. We don't know any other way to compete," he said.
"We settled a tough game against a competitive team. At the start, we were able to surprise them with Koke as a playmaker and we disorganised their defence. We had a great first half.
"We've played with every system this year. We'll play the game [on Wednesday] in a way the team needs.
"We're going to face an opponent with very important players in midfield. They'll be up for it and I'll choose the team based on that."