The 23-year-old has six international caps to his name so far, but has not appeared in the team since current Brazil coach Mano Menezes took over a year ago.
Marcelo's willingness to play for Brazil was called into doubt when his withdrawal from the squad due to play a friendly against Scotland in June due to injury was disputed by the coach. He was then not included in the national team's setup in the 2011 Copa America.
Marcelo dispelled any doubts about his loyalty, insisting that he has never intentionally missed an international call-up
Speaking ahead of Brazil's friendly match against Ghana at Craven Cottage, Marcelo said: "It could look like a lack of commitment, but I have always wanted to be in the Selecao and help my team-mates.
"I have served the team from the very start, even on long trips. They are the best, so why wouldn't I want to be involved?"
"It is not like me to ask to be withdrawn from the Selecao."