Marcelo believes the only reason supporters jeer footballers is because the player needs to improve something in their game, with team-mate Karim Benzema getting whistled in Real Madrid's 3-0 win over Las Palmas.
Madrid bounced back from their defeats to Girona and Tottenham with a straightforward victory on Sunday, but Benzema and Cristiano Ronaldo endured a frustrating time in front of goal.
Benzema missed a couple of particularly presentable chances and found himself the target of whistles from some sections of the Santiago Bernabeu crowd, with the French striker scoring just two goals in 12 games across all competitions so far this term.
"I'm not going to talk about injustice because everyone here has been whistled," Marcelo told reporters.
"If they whistle you, you have to improve something. It's hard to play when you're whistled but you have to train like Benzema does, face it like he does.
"Whistles are part of football. It can't all be wonderful."
The Brazilian also added that Benzema and Ronaldo are the first ones to be annoyed with themselves if they do not get on the scoreboard.
He said: "Well, they've been working for the team, I've seen them playing well.
"I'm asked this because they did not score, it's normal. They're really angry because they have not helped by scoring goals, but they're happy for the victory."
