The Mozambique wing-back joined Sunderland over the summer from Atletico Madrid and has become an instant first-choice for the Premier League surprise packet.
Pereira told ChronicleLive: "I worked at FC Porto with a coach called Luís Gonçalves. He invited me to join the technical team in Mozambique.
"It was there when I met Reinildo, and he was my player. At the time, he was playing for Lille in the French First Division, and he was one of the players who had a big impact on my career.
"He was playing at a big club in Lille and had a lot of potential. He made an impact on me because he's a guy that's very humble.
"He wants to learn more and more every single day. It's no surprise to see him doing well now and the four seasons he had at Atletico Madrid were not a surprise. I predicted it because of the personality he had."
On Reinildo's move, Pereira also said: "I think he wanted to prove a point and play in the Premier League. It's the number one league in the world.
"It can be an experience for him to live there, it's a very good place to live and to compete. You have the best players in the world in that league.
"It's an opportunity for the players, for the coaches, even if you're working in the first or second division. In this moment, he is playing at a big club in Sunderland."