The teenage midfielder left Barca for PSG last month for a fee of €8.5m, with his buyout clause having been set at €6m.
Asked about the situation, Deco told Sport: "He decided to leave the club. There's no club like Barça, and he's not the only one who's left.
"We spend two or three hours a day with the players at the Ciutat Esportiva, but we're not part of their daily lives, we're not in their heads. He could also be playing for the Juvenil A team in the Youth League because that's what's appropriate for his age.
"The news has been blown out of proportion because he was a player who was part of the first team setup. He had a release clause, and we didn't manage to renew it in time.
"We had an agreement with his agent that we would sit down to negotiate his renewal when he turned 18. After that, things moved quickly, and there's nothing more to say."