Palmeiras youth chief Joao Paulo Sampaio believes Estevao Willian can become the best in the world.
The 17-year-old is set to sign for Chelsea in the summer if a deal can be agreed.
The Blues are desperate to beat out other top clubs in Europe to his signature.
Speaking to FIFA, Sampaio said: "One thing these kinds of players have is a strong personality, a big ego to say: 'I am, I can and I will'.
And they do it. For these out-of-this-world talents, things come easy. It's difficult for your average player, who make up the vast majority."
On fans calling the youngster Messinho, Sampaio added: "He prefers Estevao.
The Messinho thing was put on hold, but his game is very similar to that of the Argentine."