The 28-year-old needs just one goal to reach a century of strikes for the Reds, but Benitez feels he can go on to eclipse that mark.
He said: "We are lucky to have the best midfielder in the world. He scores great goals that few others can manage.
"But he can score a lot more. Once he has scored his 100th, then we will give him the objective of maybe 150."
The influential central midfielder scored twice in Tuesday's Champions League victory in Marseille to take his tally to 99 goals.
And Benitez told the club website: "It just shows the quality and ability of Gerrard. He is a player who can play anywhere and score fantastic goals. Not just normal goals, but we are talking about fantastic goals too.
"You also have to play in a top side because at the end of the day you need to attack and create chances. It's not easy but he is still young and I think he will score a lot of goals and maybe he will have a record as a midfielder.
"If he keeps playing as well as he is then why not? And if he keeps taking the penalties it will be easier too. If he can score against Stoke I will be really pleased."