Terry was originally aiming to be fit to for the Club World Cup earlier this month but setbacks have seen him remain on the sidelines.
Benitez said: "Two days ago it was one little step backwards, but now one step forwards. We cannot say when he'll be available.
"The doctors say it's difficult with an inflammation. The next two or three days, he won't be available, that is clear. He just did the warm-up with the team the other day. I don't know how long (he will be out)."