Players who cover their mouths when confronting an opponent will be immediately sent off at this summer's World Cup.
Cafu was speaking to Marca at a charity match.
"Let's hope a South American team lifts the World Cup," he began. "We'll be very well represented, and we hope it comes to our continent. Of course, it could be Argentina; they're the champions, and so are we.
"It's a real shame about (Eder) Militao's absence; he can play centre back or full back. (Carlo) Ancelotti will know how to replace him.
"Brazil isn't just Vinicius, although he's clearly a key player, but everyone will be important. The responsibility for Brazil, as five-time champions, is always greater."
On the Vinicius Law, he added" "I think it's fantastic. You don't have to cover your mouth when talking to teammates, rivals, or friends when playing football; everyone has to show themselves as they are."