Hello @AdamTyler-3590 Thank you for reaching out to us on Microsoft Q&A platform. Happy to help!
From the tile of the post, I understand that you want to know if it is possible to exclude disk which already replicating. Unfortunately, you cannot exclude a disk from a VM that is already actively replicating with Azure Site Recovery. If you want to exclude a disk, you need to disable protection for the VM, exclude the disk, and then enable protection again.
Please note that after you enable replication, you can't add, remove, or exclude disks for replication. If you want to add, remove, or exclude a disk, you need to disable protection for the VM, and then enable it again.
Hope this helps! Let us know if you have any other questions.
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