The 26-year-old signed for the recently-promoted Premier League club this week on a five-year contract for around £8.7m, leaving Spanish side Eibar after only one season.
Rafael Benitez called the former Villarreal, Girona and Manchester City centre-back, who initially didn’t believe it was the Magpies boss on the phone.
He said: “Getting a call from Rafael Benitez was absolutely amazing, and I could only say yes. It was like a dream.
“When I got the call, I thought it was a prank so I didn’t say anything. After a few hours, I said, ‘Yes, that’s Rafael Benitez’, so I had to say yes.
“He was very important to my decision. For many years, my career was going up and down and up and down.
“He’s a great coach. Everyone knows him and he has won lots of trophies – that is Rafa Benitez. Newcastle is a very big club with a fantastic history.
He added: “As soon as Rafa phoned me, we had a good discussion and there was no question about whether to come or not.
“It’s always been a dream. I have played in Spain and France, and everyone was telling me that the English league was very important and very intense.
“I really wanted to come and play here, and hopefully I will be able to prove that I am worth it.”