The young defender has penned a deal to 2028.
Corona said: "We are very happy with this extension, which reflected César's contract. We believe a lot in him, he has been showing for many years that he can be a Valencia CF player and he has achieved it. He is a kid that we like to put many times as an example, silent, hard-working... And what can we say about his Valencianista DNA.
"You all know that he has been a fan before being a professional of the Club, which is a reason to be very happy for the achievement of this contractual objective."
Corona also said: "We make decisions thinking in the medium to long term. In January we sat down with the boy, the coaching staff and the sports management staff and we thought that he could be a very important step for 2024-25. That's how it has proved, he comes tremendously prepared.
"He has had an impressive half-season at Real Valladolid, I know he has been on the lips of all Spanish soccer and has been a surprise for many, but not for us who knew him. His performance and his experiences have been so high that he is ready to compete with the best players in the world."