Benitez refused to name the England midfielder but would not say that the long-running transfer saga was over.
Villa boss Martin O'Neill conceded last week that his captain might leave but reports have suggested that a proposed fee of £18m was the sticking point.
"The situation is not a question of money," said Benitez after Liverpool beat Lazio 1-0 in a friendly on Friday.
"We have a good player (Alonso) and we have another good player coming in soon.
"We can improve the squad, so we will try to do that. We will bring in one more player if we can.
"I do not know when but clearly we have problems on the left, Kewell has gone, Aurelio is injured and Leto cannot get a work permit.
"Babel is away in the Olympic Games. Maybe he can come back and fill that role, but I know we can improve in this area.
"Who comes in? It could be another left-sided player rather than a central midfielder.
"Maybe he can play in three different positions, that is a positive thing. I am talking about one player, but I won't say the name."
