Real Madrid management is pleased with Casemiro's progress with the Castilla.
The Sao Paulo midfielder arrived on-loan in January.
"We have 25 players available and all of them are very good. There are players from Castilla and Real Madrid C who are having a great season. We are keeping an eye on them and when we think they are ready to make their debut, they will," said Real No2 Aitor Karanka.