The Dolphins have allowed their opponents to score touchdowns on just 37% of the time when they reach the red zone forcing them to kick field goals, which ranks them in the top 10 in the league.
Ellerbe told the Miami Sun-Sentinel: "It means that's we're doing something all right but we're eight steps from where we want to be because we want to be number one.
"It definitely has to get a little bit tighter in the red zone. You feel the team is going to make a couple of plays in the field, but it's [critical] time when you get down in the red zone.
"To give up a field goal, you don't want to do that, but that's a win. You don't want to give up six, seven points."