Pereira shares a dressing room with Wayne Rooney and Angel De Maria and trains alongside Robin Van Persie and Nani.
"In the beginning for me, it was like, 'wow', a shock," said Pereira, who does not turn 20 until January. "But after a while, you get used to it and they are just normal people. They help you."
There are almost 40 players in the wider Manchester United squad, from established professionals to hopeful youngsters.
Competition for places is fierce but Pereira has been impressed with the mentoring and mateship.
"Everyone is competing for a spot but, if they see a young player who can be a good player, they help you," said Pereira. "They speak with me, tell me what to do and what not to do ... We're more like a family club."
Pereira was born and raised in Belgium, where his father spent more than a decade playing professionally. By the age of nine, he was in the PSV Eindhoven system in Holland before Alex Ferguson convinced him to move to Manchester in 2011. At the same time, he was representing Belgium at youth level, turning out for their under-15, under-16 and under-17 teams, although he later opted for Brazil.
He has progressed well through the ranks at United, culminating in facing Spurs in the Premier League in March.
"It was like a dream come true," he told British media. "To be fair, when I came on the pitch, it looked like I was dreaming. I felt like I was playing a video game then, afterwards, I got used to it. I didn't think about getting tired as I was just running as hard as I can."
The tournament in New Zealand can only help his cause, with United staff likely to be watching.
Pereira has impressed, particularly against Hungary in the second group match. He set up Brazil's equaliser before stepping up to slot their winning penalty in the 86th minute. But those in yellow shirts, especially the playmakers, need broad shoulders.
"There is a lot of pressure in that position," said Pereira. "But even when you put the jersey on, you have a lot of pressure. Brazil has [the reputation] so we have to do well, otherwise people are going to talk and won't be happy."