The experienced striker has been widely criticised at this summer's World Cup, but Marcelo has insisted that the forward plays a key role for the national team.
"In this team everyone has the ability to make play, dribble and create dangerous situations," Marcelo told reporters at a press conference.
"In this team, it's not important who scores the goals. When someone scores, it's as if we'd all scored. Fred is a leader on and off the pitch."
Brazil return to Group A action against Cameroon on Monday.