Barça saw off competition from other European clubs to secure the clause, which allows them to buy either player for around €35 million, and winger Angelo is of particular interest.
Angelo will not turn 18 until December, so the next step is to monitor how he develops before deciding whether to bring him to Europe.
“I deal with the situation in the simplest way possible," Angel has told Sport. "As Barça have a preferential option, I just have to play football, I don't have to worry about anything else because I leave it with my parents, with my agent Marisa and with Santos. I only have to worry about playing football."
“Obviously I am happy because Barcelona are watching me, as are other big clubs in Europe, but I have to think about continuing to be happy at Santos. I am very proud to be here playing for the club that I love and has given me everything."
He added: "Perhaps this agreement between the clubs could be interpreted as a seal of [my] quality, but, for me, we must not forget that, at this moment, the main aim is to be playing for Santos, a club where Pele and many great players have played. Playing here already shows that you have great value."