Effects of potential distribution along auroral field lines on the field-aligned current density are examined for a specific type of field-aligned potential distribution excluded by the Knight-Fridman-Lemaire (KFL) formula. It is shown that the field-aligned current density can be significantly reduced from the current density originally estimated by the KFL formula if the potential drop is concentrated at low altitudes (4000 km). This result can provide a possible explanation for the observed field-aligned current pattern across the discrete auroral forms.