The player has returned to West London following a four-month loan spell at West Ham in which he made just six appearances.
Benitez said: "He is here now but he's injured and he's working with the physios. We will see what happens.
"The question is how many players we have - we have six players in these positions. He's a very good player, no doubt about this, but again I would say we have six players in these positions. We have to manage the situation."
Benayoun, who also spent last season on loan at Arsenal, has a contract until June 2013 but under FIFA rules is able to negotiate with other clubs now.