An apparatus and a method for influencing the frictional conditions between an upper roll and a lower roll of a roll stand of a hot-rolling train for wide strip or a cold-rolling train for strip. The apparatus includes a spraying device arranged at the entry side of the roll stand for spraying a defined quantity of liquid in the direction of the roll gap and a control device for determining the quantity and discharge of this liquid, wherein used as a control variable is a predetermined or also computed variable in connection with the actual roll torque of the lower roll or/and the upper roll.