Real Madrid's Marcelo: 'I am the world's best left-back'

Real Madrid defender Marcelo believes that he is the best left-back in the world.

The 24-year-old, though, says that he is always looking to improve himself.

"I think I am the best left-back in the world because I have to believe in myself," he told Globoesporte. "I have to think about myself and continue growing [as a player]."

Marcelo joined Madrid from Fluminense in 2007.