"When the technical director at Valencia decided to sign him I gave him every support," said Benitez.
"He was initially signed for the reserve team but in pre-season I said: 'He will stay with us in the first-team squad'.
"We were surprised to see how much energy he had and how hard he worked. He was so focused, is a good professional and a nice young man.
"As a manager he is the kind of player you like to have when he is young because you can work and teach him, he is like a sponge."