He said: "Anderson has been absolutely superb. The boy has got something special.
"There was an urgency to get him once we'd scouted him, even though he had broken his leg and had been out for four or five months. The reports we got were saying that he was the best young player in the world.
"At the time, I was saying 'For God's sake, let's calm down a bit here'.
"But we're delighted with him and he has proven himself to be a true central midfielder."