Former Real Madrid chief Pedja Mijatovic feels Marcelo is lacking competition.
Even though Los Blancos brought in Theo Hernandez last summer, the Montenegrin simply doesn't think the youngster is good enough yet to make the Brazilian fear for his place.
"Marcelo has been at Real Madrid for 10 or 11 years and is surely one of the best left-backs in the world," he told Radio MARCA.
"But a lot of players lack some more ambition once they've won everything.
"There is also a lack of competition.
"You must bring in players who make the starter think a lot [about his starting place].
"Relaxation is a very dangerous thing.
"When you don't have much competition, it's dangerous.
"With respect to the others, he doesn't have the competition to feel worried."