The England midfielder is currently sidelined with a hamstring injury but could make his comeback against Real Madrid in the first leg of their Champions League last-16 tie at the Bernabeu on February 25.
"I hope and wish that he will be back soon. He has no natural replacement," Torres said.
"Every side has a main reference, a home-grown player, someone who lives and breathes the club.
"Other players come and go, but that player remains. Here, our reference player is Gerrard. Liverpool FC is Gerrard plus 10 more. He's irreplaceable."