Higuain struck twice in the 5-2 win.
Karanka said: "The other day in Vigo we said it. He was off target in front of goal and today he has scored. I say the same as then. We know what Pipa is like. We don't need to worry about the chances that are missed, the important thing is to create them in the first place. Today he has scored and that is important for him. The best thing is that he gets the confidence in front of goal that strikers need."