The 22-year-old, who joined the club as a 16-year-old in 2012, has impressed during loan spells with Valencia and Granada over the past two seasons.
"I told him (Jose Mourinho) that I felt ready to compete," Pereira told Het Belang van Limburgwhen, in reference to a chat he had with the United boss.
"He was happy to hear that and said I would get my chance. Now we will see how it goes in pre-season. Then we are together again, but of course I hope to convince him.
"Breaking through at Manchester United is and remains the big dream.
"After two good seasons in Spain, I know that I can always go there. Valencia wanted to keep me, but at the moment my goals are in England.