Cardoso got into Monday's match under pressure after entering the year with Sundowns trailing Orlando Pirates in the PSL title race.
This came as Pitso Mosimane was being linked with a return to Masandawana to replace the Portuguese who talks about his future.
“The problem is nowadays, people discuss football on the phone, and they speak about things they have absolutely no idea of,” said Cardoso.
“That gives a lot of echo to things that don’t even exist, and that is a question, people are discussing things that they would like to happen.
“Having a phone, a blog, and some followers give echo to people who don’t know what they are speaking about," Cardoso added.
"Look, Sundowns is a club that’s ruled from the inside to the outside, not the other way around.
“There’s a strong leadership, strong sports direction, a strong coach, and a strong locker room. The doors of Chloorkop are so strong that those things like that don’t enter; we are united.
“We are working hard to please our fans. And we need them not to let themselves be poisoned by the outside, keep supporting us."