The defender made his debut for Real last week.
After Castilla suffered another defeat to Antequera on the weekend, Raul said: "Yes, Asencio's promotion has given an extra boost to the youngsters, it has given them the hope of reaching the first team and also the aspect with respect to the discussion that compares our youth sector to that of Barcelona.
"Real Madrid, as a club, has experienced one of the best moments in its history and the demands of the first team are not at all easy, but with Asencio's success it shows that the boys are prepared, like others who have been here and are triumphing in other leagues or in other teams."
He also said: "I think that Real Madrid's youth teams are prepared, but what is clear is that Real Madrid has the best youth team. There are great players and great players will continue to emerge for the first team, with the difficulties and demands that come with it because there are the best players from all over the world."