new NIC on GTMs in Sync group

Hi,

We have two production GTMs configured in a SYNC group. They are Virtual Machines and each of them with three NICs: management, internal and external

Our plan is to add a new NIC [fourth] to each of them and hook a new VLAN there, so they can access a new subnetwork on that VLAN.

Will this new NIC disrupt the normal function of the GTMs while we create it and add the new VLAN? Is it something we can do without affecting the SYNC group and the normal behaviour of the GTMs?

Thanks