Maiorino was Las Palmas sporting director as Pedri was sold to Barca last year.
But he revealed to Sky Italia via TMW: "I had told Milan because I had almost a moral obligation towards the club that had raised me at work.
"I remember that they had gone to see him in Malaga but Barcelona were already ahead in the negotiations. It is difficult for an Italian team to take a football player like that, also because he had not made the youth national teams.
"Barcelona had the skill of closing quickly."
Maiorino was instrumental in Las Palmas signing Pedri as a junior player.
Spain's Euro 2020 star only left Las Palmas a year ago to join Barca. It was with Las Palmas where Pedri was handed a first team debut by Pepe Mel before making the move to the Blaugrana last summer. At Las Palmas, Pedri played 37 games in a full season of first team football for 2019/20.
Last season, the midfielder managed 52 appearances for Barca, scoring four goals and producing six assists. Pedri was a star for Spain at Euro 2020, with their run ending last night in a semifinal defeat to Italy.
The teen started all of Spain's games at the tournament.
- updated July 7