Although he was on the scoresheet as Real Madrid bowed out of the Copa del Rey by suffering a 4-3 defeat to Real Sociedad on Thursday, the 31-year-old Brazilian failed to convince with his performance.
A combination of injuries and poor form has restricted Marcelo to just seven La Liga appearances this season as summer signing Ferland Mendy has taken his place on the left side of defence.
Marcelo has been one of Real Madrid’s faithful servants having joined the club from Fluminense in 2007, and he has won four La Liga titles, four UEFA Champions Leagues, two Copa del Reys among other major honours in his time at the club.
Ahead of Real Madrid’s La Liga game at Osasuna on Sunday, Zidane has made his feelings known about the reaction to Marcelo’s performances.
"It's upsetting because he gives his all when he plays – not just Marcelo, all the players do – but this isn't going to change. I can say it's upsetting, it's not good because they go out there and play to their maximum,” Zidane said.
"The fans who were there saw that. The fans have a role to play – they could be upset when we get knocked out, but I know they know we've given 100 per cent.
"I think Marcelo gave his all the other day. The knives come out when you lose. When we lose, everything gets analysed. The important thing is my players give 100 per cent and he did, I think.
"He's been an important player for many years and I'm sure he's going to continue to be important until the end of the season
"It's very difficult with 50-60 games to play your best football always, so there are ups and downs. There's a long way to go and everyone is needed until the end of the season."