Pereira, on his first competitive start for Man United, scored a sublime free-kick to give his side a two goal cushion at Old Trafford.
Anthony Martial eventually rounded off the scoring in what was a hugely positive night for United’s youngsters.
Van Gaal explained that Pereira’s versatility bodes well for his future chances in the first-team.
“It was his first line-up match (start) and I think he did rather well. He scored a fantastic, important goal and I’m pleased but he has to compete, for example, with Juan Mata, Memphis Depay and Ashley Young so it shall be difficult for him,” van Gaal said.
“He can play in the no.7, 10 and 11 positions. Lingard can also play no.7, 10 and 11. I have multi-functional players but they have to compete with other players. It is dependable on the level of the players. I always put the best player in the line-up when he is working for the team.”
The evening couldn’t have gone much better for Pereira and he firmly announced himself to the Old Trafford faithful. However, the notoriously difficult to please van Gaal may not throw him straight into the deep end just yet. Pereira will have one eye on the fourth round tie against Middlesbrough as another opportunity to make an impact.