"Sissoko was a player that grew a lot with us and he's a fantastic boy," said Benitez. "He was called the new Vieira a few years ago. He played many times when he was 18, 19 and I think he has the energy that we need in the middle.
"He has incredible ability for his age. He is 20, I saw Vieira when he was 18-years old and he was no better than Sissoko. Sissoko runs more than Vieira. In a couple of years he will be more dynamic than Vieira and a better player."