The Catalan giants cruised to victory despite playing the last 20 minutes with 10 men after Gerard Pique had been sent off.
Koeman spoke about what he liked about his team and also where he felt they need to get better after the full-time whistle.
“When you win a game, get three points and score five goals, you can be happy,” he said.
“I think after the break we played 25 really good minutes. But what I liked less, and we have to improve and avoid, are those moments in the game when we switch off.
“If we are capable of playing the whole game at the same intensity and, above all, with that high rhythm with the ball, we are a really good team.”
Source | Sport
The Dutch coach now turns his attention to his first Clasico as Barcelona boss on Saturday at the Camp Nou. Koeman has plenty to ponder regarding his team selection after some impressive performances from his young stars against Ferencvaros.