However, it doesn't mean he's not concerned about their production.
"That's an area where we need to improve on, but we haven't had opportunities in the games to really just line up," Fisher said after Monday's practice.
The Rams finish the preseason on Thursday against Baltimore.
The Rams are making a transition to a life without perennial 1,000-yard rusher Steven Jackson, who left via free agency to Atlanta.
They are averaging a little more than 3 yards a carry from their top four running backs, a year after the team ranked 19th in the league in yards per game with a 107.1 average.