diff --git a/pkg/volume/csi/csi_attacher.go b/pkg/volume/csi/csi_attacher.go
index 494e46d8eb0..c3f2213558c 100644
--- a/pkg/volume/csi/csi_attacher.go
+++ b/pkg/volume/csi/csi_attacher.go
@@ -413,30 +413,17 @@ func (c *csiAttacher) Detach(volumeName string, nodeName types.NodeName) error {
 		return errors.New("missing expected parameter volumeName")
 	}
 
-	if isAttachmentName(volumeName) {
-		// Detach can also be called with the attach ID as the `volumeName`. This codepath is
-		// hit only when we have migrated an in-tree volume to CSI and the A/D Controller is shut
-		// down, the pod with the volume is deleted, and the A/D Controller starts back up in that
-		// order.
-		attachID = volumeName
-
-		// Vol ID should be the volume handle, except that is not available here.
-		// It is only used in log messages so in the event that this happens log messages will be
-		// printing out the attachID instead of the volume handle.
-		volID = volumeName
-	} else {
-		// volumeName in format driverName<SEP>volumeHandle generated by plugin.GetVolumeName()
-		parts := strings.Split(volumeName, volNameSep)
-		if len(parts) != 2 {
-			klog.Error(log("detacher.Detach insufficient info encoded in volumeName"))
-			return errors.New("volumeName missing expected data")
-		}
-
-		driverName := parts[0]
-		volID = parts[1]
-		attachID = getAttachmentName(volID, driverName, string(nodeName))
+	// volumeName in format driverName<SEP>volumeHandle generated by plugin.GetVolumeName()
+	parts := strings.Split(volumeName, volNameSep)
+	if len(parts) != 2 {
+		klog.Error(log("detacher.Detach insufficient info encoded in volumeName"))
+		return errors.New("volumeName missing expected data")
 	}
 
+	driverName := parts[0]
+	volID = parts[1]
+	attachID = getAttachmentName(volID, driverName, string(nodeName))
+
 	if err := c.k8s.StorageV1().VolumeAttachments().Delete(context.TODO(), attachID, metav1.DeleteOptions{}); err != nil {
 		if apierrors.IsNotFound(err) {
 			// object deleted or never existed, done
@@ -641,13 +628,6 @@ func getAttachmentName(volName, csiDriverName, nodeName string) string {
 	return fmt.Sprintf("csi-%x", result)
 }
 
-// isAttachmentName returns true if the string given is of the form of an Attach ID
-// and false otherwise
-func isAttachmentName(unknownString string) bool {
-	// 68 == "csi-" + len(sha256hash)
-	return strings.HasPrefix(unknownString, "csi-") && len(unknownString) == 68
-}
-
 func makeDeviceMountPath(plugin *csiPlugin, spec *volume.Spec) (string, error) {
 	if spec == nil {
 		return "", errors.New(log("makeDeviceMountPath failed, spec is nil"))