The Portuguese mentor stopped short of naming any teams or individuals but made strong claims suggesting that match officials were being influenced.
Cardoso made the bold allegation after Sundowns’ 2-1 victory over Gomora United on Wednesday night, a result that secured their place in the Nedbank Cup round of 16.
"If we start introducing VAR in matches, things will improve because there will be no suspicious activities or individuals. Here in South Africa, it becomes very interesting when officials from certain teams visit referees on the morning of the matches – look out for that, because I saw a photo today.
"It's important that we look out for that. It's the first time I have seen officials from one team visiting the referee from that game at night. That happened recently – very recently, maybe yesterday," said Cardoso
The vocal Sundowns mentor also revisited his opinion on the state of PSL match venues – remarks that have previously put him in the spotlight.
"We need to create conditions to show that we are improving, and you [journalists] have a very important role to play in this: promoting the important side of the game not the things that are not important, you should promote the right side of the game."
Cardoso also used his native country as an example to back remarks about improvement in the modern game.