Speaking to La Repubblica, he said: "For everyone, I will always be Casemiro… It's all Sao Paulo's fault. It all started when I played one of my first matches for Sao Paulo, the club where I went through the ranks, from the youth team to the first team [from 2002 to 2013]. They accidentally wrote my name with an 'e' on the shirt. I played very well.
"I’m a very superstitious person. I told the club: ‘There’s no need to change it — things are going well.’ It was a one-match mistake, and now I’ll carry it with me forever."
The spelling stuck ever since, becoming part of his footballing identity through Real Madrid, Manchester United, and Brazil.