SN65LVDS31: SN65LVDS31 Output Impedance when unpowered

Part Number: SN65LVDS31

Tool/software:

I have the circuit in the image. I use one differential pair for two LVDS drivers and two receivers. The idea is to use one at a time, keeping the other as a backup. I understand the receiver will not be an issue due to its high input impedance.

However, I am unsure about the driver. The datasheet states driver outputs are high-impedance when disabled or unpowered. Does this mean I must force a zero to the power input, or is leaving the power unconnected sufficient?