Casemiro insists he could never contemplate joining Barcelona due to his love for fierce Clasico rivals Real Madrid.
The Brazil midfielder struggled for playing time at the Santiago Bernabeu under previous head coach Rafael Benitez, but became an integral part of Zinedine Zidane's plans at Madrid.
"I'll never play in Barcelona, because in Spain I am a Real Madrid supporter," he said.
"Real Madrid is much more than I expected. I love waking up in the morning and going to Valdebebas [Madrid's training base].
"I love being with the players, joking, working, learning. I try to live football every day.
"Real Madrid is my life today."
Casemiro was also questioned about the talent of his international team-mate Neymar, who is part of Barca's devastating three-prong attack alongside Lionel Messi and Luis Suarez.
The 24-year-old believes Neymar has all the talent to become the best player on the planet, but is tipping club-mate Cristiano Ronaldo to win the prestigious Ballon d'Or award.
"Neymar's career, there is still more to come," he added.
"But all the football that Cristiano Ronaldo has done over the last 10 years is to remember for a lifetime. Neymar has everything to get it.
"[But] Cristiano is going to win the [Ballon d'Or]."
"The best players in my position are [Sergio] Busquets, Thiago [Alcantara], Gabi, Xabi Alonso," he added.
"Busquets is a great player, how he plays the ball, his positioning, his balance on the pitch."
