Once you configure a job with an excluded disk, the excluded disk will not participate in backup.
If still, you want to configure the excluded disk in the restore VM then you can attach the disk from vCenter level.
Edit the VM property and add the existing disk, but before doing this you need to capture the existing disk path.
I have already created a backup job, you may refer Create Backup Job in Veeam Backup and Replication 12 to create a backup job.
Now I am going to modify the Backup Job that I have created.
Right Click on the Job -> Click Edit
Go to Virtual Machines -> Select the Virtual Machine
Select VM click on Edit
Select the Disk that you want to Exclude
Once done click Finish