The Brazilian made his first competitive start for the club against Ipswich Town on Wednesday night and capped an impressive performance with a superbly-taken free-kick, which put United 2-0 up on the night.
“I asked Juan for the ball and he gave it to me,” Pereira told MUTV.
“We’ve been practising together and he trusted me.
“It’s very special for me to score my first goal, a free-kick at the Stretford End as well. It’s just like a dream come true. I’m very happy for my family, for impressing my manager and doing well for my club.”
Louis Van Gaal said the youngster had made a big impact on his debut but added the 19-year-old had plenty of space for improvement.
“He had a big participation on the game because he scored the free-kick in a fantastic way,” he said.
“We know that, he’s doing that in training, so that’s the reason he takes the free-kick.
“But, like all the other players, there is a lot of space of improvement for Andreas.”