Marcelo says Real Madrid are already focusing on adding more titles to last year's Champions League triumph, starting with the UEFA Super Cup against Sevilla.
The LaLiga sides meet in the European showpiece on August 9 in Trondheim, with Marcelo hoping Cristiano Ronaldo is fit to play following his exploits at Euro 2016.
Ronaldo's Portugal lifted the trophy following a 1-0 win over France thanks to Eder's extra-time goal, but Ronaldo missed much of the action after limping off in the first half.
"I spoke with Cristiano and congratulated him, Pepe too," Marcelo said. "I don't know much about Cristiano's injury, although I hope that he'll be ready for the Super Cup.
"We've won the last Champions League, but now we have to work and our head is on improving to win more titles.
"We are thinking about the Super Cup, the beginning is always a bit hard, but we are focused on the Super Cup."
Madrid are reported to be open to selling striker Alvaro Morata after enforcing the buy-back clause on his Juventus deal, but Marcelo suggested the Spain international could be useful to head coach Zinedine Zidane.
"We know that Morata always has been a great player," Marcelo said. "Before he was young, now he has more experience and is going to help us a lot.
"I think that the squad is fine, I'm not the one who decides. Those we have are great players and those we don't have are great too.
"The squad that wins always is the best. I have spent several years without winning titles, although we've had quality players. It is difficult to say if it is the best squad or the second best. But each year Madrid tries to win titles."
Marcelo, who recently had the Champions League trophy tattooed on his leg, added he hopes defender Nacho is retained by the club.
"I've known Nacho since Castilla, when he came with us, I have a lot of affection for him," the left-back said.
"Of course, everyone wants more minutes. I want Nacho to stay, the team wants him to stay, he is important to us both in matches and in training.
"Since I joined Real Madrid I was taught to fight for the team. I hope to be here for many years, leaving my skin for the team. Leave? Only if Madrid throw me out. I want to stay in Madrid, I want to continue my life in Madrid."