The Real Madrid left-back believes the reigning world and European champions remain the favourites to lift the World Cup in his homeland of Brazil
The Selecao beat Vicente del Bosque's men 3-0 in the final of the Confederations Cup last summer, with many onlookers pointing to that result as the start of a power shift in the international game.
Spain defended their European Championship crown in 2012 having lifted the World Cup two years previously and Marcelo says they remain the standard bearers on the international stage.
He told reporters: "I think Spain are the best team in the world right now. I don't think that has changed because we won the Confederations Cup. They respected us before and they still do now."
Marcelo was left out of Brazil's World Cup 2010 squad and as a result is refusing to take his place in the starting line-up for granted under Luis Felipe Scolari this time around.
He added: "I certainly don't think of myself as the owner of the No.6 shirt.
"I've been working since I was 17, when I started playing for Fluminense, which helped me a lot, I grew a lot there and even more at Real Madrid.
"In my head I always had the idea of giving my best and playing for the Selecao. Unfortunately I didn't make it to 2010, but my hopes were never dead and today, thanks to God, I have the chance of being in a World Cup."
The 26-year-old enjoyed a morale-boosting end to his club season with Madrid after scoring in extra-time in the final of the Champions League after coming on as a second half substitute in the 4-1 win.