Mourinho, who left Chelsea in 2007 following a three-year stint in London, is widely expected to leave his managerial role with Spanish outfit Real Madrid at the end of the current season.
That has resulted in numerous reports that he will return to the Blues - speculation that Benitez has now suggested could be proved to be correct.
"The next year there will be another manager," the Spaniard told reporters. "I think everybody knows who will be here."
Chelsea won the Premier League twice under Mourinho's guidance, as well as one FA Cup and two League Cups.