The defender said: "Berba is a fantastic footballer who is going to prove his worth to us over the years. He makes the game look easy and that tends to make people think he is not trying. But any suggestion that he is lazy is wrong.
"He has a wonderful football brain, a deep knowledge of the game and a true awareness of everything that happens on the pitch. I have heard some say he is not worth the money we paid for him. That's ridiculous. We will see him get better and better."