The England midfielder has returned to training after recovering from a groin injury. It is a welcome boost for Liverpool ahead of the match, especially as they could be six points adrift of leaders Manchester United come kick-off.
United are in action on Saturday when they face struggling Middlesbrough at the Riverside Stadium.
Benitez said: "Steven is doing well and is training with the rest of the team. I think he will be fit and available for Sunday.
"It is good news for the team and for him because he can be a key player for us over the remaining games.
"Without Steven the squad has been playing well and scoring goals, so that is positive."
Benitez insists his thoughts are only with continuing their title bid and not potential business in the transfer market after Xabi Alonso was linked again with a move to Juventus.
"I was reading the press and they are talking about different players," he told Liverpool's website.
"I can guarantee today that we are not thinking about selling anyone. All we are thinking about is to do our job and to try and win the Premier League title, if possible.
"After that you never know what can happen in the market. Clearly, at this moment, we are just preparing for winning games."