Real Madrid midfielder Casemiro insists Barcelona's flying start to the season counts for nothing yet ahead of Saturday's Clasico showdown.

Madrid welcome Barca to the Santiago Bernabeu in the hope of inflicting a first defeat upon Ernesto Valverde's men since triumphing in the Supercopa de Espana in August.

Barcelona's 13 wins and three draws in the top flight gives them a six-point lead over Atletico Madrid at the summit, with Zinedine Zidane's side 11 points in arrears with a game in hand.

Nevertheless, Casemiro and his colleagues have shown their taste for trophies over recent seasons by winning LaLiga last term and back-to-back Champions League titles.

A 1-0 win over Gremio last weekend retained the Club World Cup and the Brazil international is not giving up on domestic matters.

"So far they are doing well," Casemiro told DAZN. "They are fine in LaLiga, they are fine in the Champions League too, but I prefer to talk about what my team-mates are doing.

"At the end, we will know everything: Who will win the league, who will win the Champions League.

"When Zizou [Zidane] took control over the team we weren't doing well in LaLiga or in the Champions League, and in the end won the Champions, and our fate changed completely.

"We have to keep working hard because football keeps changing, so we have to keep on working and I'm sure our situation will change, and we are working on that.

"May is where all it counts and we want to win some titles at the end of the season. But at this stage we must be in a good position too, we can't forget it, because maybe Barcelona and the rest of the teams [will be too] far from us in La Liga.

"We know the most important thing is the title and we always have to fight with the title in mind."

Casemiro has established himself as an integral member of Madrid's starting line-up since Zidane's appointment in January 2016 and he holds the Frenchman in the highest regard.

"There is no doubts Zidane is key for the success of our team because he was a player, he was a Real Madrid player, he knows the dressing room, he knows how players think and he knows how Real Madrid players think," the 25-year-old explained.

"So, for me, he is one of the keys [behind Madrid] because he is doing a phenomenal job.

"He just won an award [FIFA Best] as the world's best manager because of his work. So for us it is an honour to have a manager like him, and it is very important for us to have a trainer who knows the dressing room."