Yes this is possible. However, in order to make this work you will need to configure a couple
of things. First, on the Local Director you should configure an 'alias ip address' that belongs in this new subnet. Second, you need to configure a secondary IP address on the upstream router. This will serve several purposes. One, the servers will be able to reach devices outside their own subnet. Two, the router will now belong to this subnet and therefore will be able to ARP for the new virtual.
Hope it helps.
Best regards,
Chip Schneider
Cisco TAC