PERC H710 - Erase Disk

I have a Dell server with a PERC H710 card with two virtual disks (RAID 1 and RAID 10).  One of the drives began to fail in the RAID 10 array, so the drive was replaced with a new Dell drive.  The RAID 10 array was successfully rebuilt.  I need to erase the old drive before sending it back to Dell.  I inserted the old drive into slot 7 and it came up as foreign, so I cleared the foreign configuration.  The old drive is now in the ready state.  I would like to create a virtual disk (RAID 0 containing only the old drive) so that the old drive is fully erased.  If I try to create a new virtual disk, Open Manage says there is no free space available to create a virtual disk.  What should I do?