The 18-year-old has previously represented Belgium at youth level, but is also eligible for Brazil and he met with their Under-20s boss Alexandre Gallo recently to discuss that possibility.
However, the attacking midfielder insists that his priority at the minute is making a name for himself in domestic football before worrying about the international stage.
"I want to focus on Manchester United in the first place. I haven't made my mind up," he told Belgian newspaper Het Belang van Limburg.
"If I ever have the chance to play for Brazil, I won't hesitate. But I've always played in the Belgian national youth ranks.
"And I did feel at home there, in contrary to what's claimed in Brazil. The door's not closed yet."