If you have an exported backup, you can manually upload the VMDK files to an ESXi datastore via the vSphere Client Datastore Browser and then "Edit Settings" on your VM to "Add Existing Hard Disk". Pro Tips for Success
vmware-vdiskmanager -e "yourdisk.vmdk"
Several third-party tools and utilities can help in recovering or restoring VMDK files:
A VMDK file is a container file that stores the virtual disk data of a VM. It contains metadata, such as the disk's geometry, adapter type, and sector size, as well as the actual disk data. VMDK files can be stored on a variety of storage devices, including local disks, SANs (Storage Area Networks), and NAS (Network-Attached Storage) devices.
A small text file containing the disk's geometry and hardware info. The Data File ( -flat.vmdk ): The actual binary data.
For production environments, the most reliable way to restore is through an "Image-Level" backup.
If the VMDK won't attach or boot: