There are several players in world football that exist on a plane of reality of their own and are treated as such. Players that don't abide by the same selection or transfer rules as others if their situation changes. Barcelona's Gavi is certainly one of them.
At 18 he is already one of the most unique and talented players of his generation. His ability to blend the Xavi and Andres Iniesta grace with an inside forward that Mauricio Pochettino would pure about is astonishing. There are times when players are said to go too early, and be given too much responsibility and expectation placed upon them, Gavi isn't like that.
The way he blends midfield and attack, operating neatly but under the radar in half-spaces outside of enemy detection is the stuff of wizardry. To have such command of a ball, the tempo of a game and the spacial awareness around him is not normal.