The Spanish club announced they had reached an agreement with the Magpies for the transfer of the Spain Under-21 international.
He explained: "I met Sam for dinner and I was very happy to listen to his plans for Newcastle United.
"He treated me very well and he understands me. He knows I have to get used to a lot of new things, like changes in culture and language, but he says he is going to help me adapt to that.
"He says it will make me stronger and he will have patience with me. I am really happy to hear that.
"It will also help me to have people like Nolberto Solano and Albert Luque to speak to. Albert says he is going to take care of me at Newcastle."