The negotiations of the new Football Director might have been the key
The incorporation of the new Barça Football Director, Ariedo Braida, was a surprise, but if rumors are true, the fruits of his management would fully justify their arrival.
According to the journalist Cristina Cubero of the newspaper Mundo Deportivo, the president of a very important Italian club told the Italian Football Federation that currently midfielder of Juventus, Paul Pogba, would join FC Barcelona. The journalist said that this was Braida's merit and stressed that the signing is assumed even by parties involved in the transfer.
So Braida's agenda seems to be very well connected, not only in Italy.