disable interface / sfp on standby node

Hello,

is it possible to configure an interface that is administrative down on the standby node in a HA active-passive?

I try to explain why we could need it:

we have a leased line (10Gbit/s) and we get only one uplink. We don't want to connect this line to our backbone. If we connect it to the master node we have to manually switch the cable if the standby nodes becomes the active one. We this cables: https://www.amazon.de/gp/product/B01FPDL5YG/ref=ox_sc_act_title_3?smid=A3PA9EESTVZ0Y7&psc=1

and thought if it is possible to connect both firewall nodes with the uplink, but this is only possible if the passive node disables the "TX-line" no light ;) )

our (new) Fortigate is a 1500D cluster

regards

 philipp