The Brazilians completed the signing of De Reuck from Maritzburg United last week, with the defender signing a five-year deal with the club.
Mayinga, who nowadays works as a football analyst, believes the signing was not necessary as the player does not fit the club's style of play.
"No, he won't fit the pattern of Sundowns," Mayinga tells snl24.com/kickoff when asked if Sundowns needed the new Bafana Bafana international.
"He's a good player, let's not take anything away from him. But Sundowns demand... how do I put it? Not just any player. A player that has character. Not only for one game but consistently week in week out. And always make sure you perform at your peak. You see, a player like [Ricardo] Nascimento for an example will be very difficult to replace at Sundowns because he's unique.
"The same thing with Alje Schut when he was still at Sundowns. He was unique, it took time before they found Nascimento. So now there's Mosa Lebusa who is still trying to fit in. But Mosa Lebusa is injury-prone. There's Brian Onyango, who to me is the fastest centre-back, a good reader, a good passer of the ball, but somewhere somehow he's got a lapse in concentration.
"You see letting go of Wayne Arendse, it was a premature decision. You need people like Arendse because they will give you stability come rain or shine. He's dependable."
Mayinga continues: "As for De Reuck, yes at Maritzburg he will shine. I've got nothing against him he's a good player, he reads the game well and is able to anticipate. But I don't think he can fit the Sundowns style of play, unless otherwise [proven]. I think he still has to prove us.
"Yes he can close [Samir] Nurkovic but the way Sundowns is playing, you saw what [Mothobi] Mvala did against Leopards? Can he sustain such kind of pressure [De Reuck]? I'm not saying he is a bad player... because once you start saying he won't fit, people think you are saying he's a bad player... no. As a Sundowns defender you must be able to handle three players at once, which I doubt is something he can manage."
When asked what might have attracted Sundowns to the player, Mayinga reponds: "Sundowns will always have an interest... remember, he is more similar to Rivaldo Coetzee. So Rivaldo is injury-prone, they have to manage him. He won't play four games in a row. But De Reuck still has to earn his stripes. Remember, Sundowns is not only playing in the PSL but also in Africa.
"You don't just buy a player because he closed down Nurkovic for two games. Remember, there's still players from Africa who are very imposing and hostile. You need to have character. Not just because you've won two or three man of the matches.
"That's the mistake we always make as South Africans because a person plays well against Chiefs, Pirates and Sundowns then the next thing we want him to be included in the Bafana Bafana squad."