Jose Mourinho handed the then 19-year-old a debut for the first team in 2013, just one month after Casemiro has graduated from Castilla.
“It was my first season as a pro. At first it was hard because the championship is completely different,” the 23-year-old told Goal.
“I learned the language and it became better. It was a good experience - I could have stayed with Castilla [Real Madrid B team]. I do not know if it was too early or not but I wanted to leave for Monaco.”
The Brazil international now has four caps for his country and has emerged as one of Europe’s most promising full-backs, attracting interest from Manchester United, but is focused solely on Monaco’s challenge for the French league title.
“There was something with Manchester [United], I think there was an interest but nothing concrete,” he revealed.
“I am settled in Monaco, we have made a good start to the season and I am focused on them."