The Selecao's experienced coach Tite departed after the 2022 World Cup and this weekend's friendly against Morocco in Tangier will be the team's first game since then.
Casemiro's huge experience and winning mentality have made him an excellent choice for the armband, handed to him by interim boss Ramon Menezes.
"There are several ways of thinking," said Casemiro at a press conference.
"We had Thiago Silva [as captain] in the World Cup but, on my part, I feel prepared. I prepared myself for this and I am thankful for the trust.
"If it's another captain, no problem because I know I am one of the leaders and I have complete freedom to speak as a captain before the group.