A free flow mitigating device for a fluid administration set includes a pump driver mechanism having a locator pin attached and positioned to register with a locator hole on the administration set, for example in a cassette. The locator pin has a surface area. A compressible material is attached to at least a portion of the surface area of the locator pin. The compressible material has a thickness such that it is frictionally received within the locator hole of the cassette sufficient to provide a retaining force to resist cassette movement during closing of a flow regulator valve of the cassette.
