"Despite being born in Belgium, the midfielder is the son of a Brazilian couple..
Andreas has played for Belgium’s U-15, U-16 and U-17 levels, but then changed teams, having featured for Brazil’s U-20 and U-23 teams.
..according to outlet UOL this Wednesday. The website claims that he was watched by manager Roberto Martinez during Manchester United’s match against Leicester City last week, and could be called up in the next few days.
UOL claims that according to people close to the player, Andreas’ preference is to play for Brazil"
He's said in various interviews that he feels Brazilian and not Belgian. He grew up in a Brazilian household, spoke Portuguese as his first language. He moved to Netherlands at the age of 9 and Manchester at 16, ergo he didn't spend his teenage years in Belgium either.
I'd be very surprised if he picked Belgium.