Zola told whufc.com: "Savio is very similar to what I was when I was 19. I wasn't the player I am now but I was very good at taking players on. That is one of the main qualities between a normal player and a special player. Especially in modern football, you don't find many players with this kind of ability.
"Savio is already a top player but one top of that he has to put other qualities. That's why I'm here. I'm going to try and give him the other bits missing from his game that will allow him to go a step higher. He certainly has qualities which are quite a rarity in modern football. Taking players on is very important.
"He will excite West Ham United fans. He is certainly one of those players who catches your eye and we are confident he is going to do it over here. But please don't forget he is 19 and he has to learn a lot. He will certainly become a very important player. But we have to allow him time to settle into the rhythms of the Premier League. I'm sure he will be a success."