Gerrard introduced the former England striker with 24 minutes remaining of Wednesday's clash with Dundee, and watched as he put the seal on a 4-0 thumping.
The 36-year-old's fifth goal for Rangers is after just six starts and three substitute appearances.
Gerrard told RangersTV: "That is what we've brought him here for, to score goals.
"It doesn't matter whether Jermain plays 90 minutes or 60 or 30, we want him to be a goal threat, and his movement is fantastic.
"I used to love playing with him. He's a dream for a midfielder because his movement tells you where to play the ball.
"It was a great pass from Ryan and a great finish, and he'll continue to do that if we provide the service for him."