The Spanish under-21 international midfielder has been persistently linked with a move to Athletic Bilbao and he has struggled for game-time at Newcastle since the turn of the year.
“He was unlucky with his injury and we were lucky because Jonjo (Shelvey) and (Momo) Diame were playing much better," Benitez explained.
“You have to understand that when you're talking about players in same position. We are lucky to have four central midfielders, they can all play. I don't feel there is a massive difference between them.
“I was talking with one player today who was asking me about his future. Some of them are very easy. We don't need to talk too much with some of them. It depends on positions. We have to start working on that, each one will be different.
“You have to at least change four or five. How many depends on the market and options and who is available. Ideally bring players to compete with the others who are playing. If you are to improve you need players to push the one here already."