diff --git a/pkg/operator/ceph/cluster/mgr/spec.go b/pkg/operator/ceph/cluster/mgr/spec.go
index de6732c62..1cf57aa62 100644
--- a/pkg/operator/ceph/cluster/mgr/spec.go
+++ b/pkg/operator/ceph/cluster/mgr/spec.go
@@ -23,6 +23,7 @@ import (
 	"strings"
 
 	rookcephv1 "github.com/rook/rook/pkg/apis/ceph.rook.io/v1"
+	rookalpha "github.com/rook/rook/pkg/apis/rook.io/v1alpha2"
 	"github.com/rook/rook/pkg/daemon/ceph/client"
 	"github.com/rook/rook/pkg/operator/ceph/cluster/mon"
 	"github.com/rook/rook/pkg/operator/ceph/config"
@@ -80,16 +81,11 @@ func (c *Cluster) makeDeployment(mgrConfig *mgrConfig) *apps.Deployment {
 		podSpec.Spec.DNSPolicy = v1.DNSClusterFirstWithHostNet
 	}
 	c.annotations.ApplyToObjectMeta(&podSpec.ObjectMeta)
+	c.applyPrometheusAnnotations(&podSpec.ObjectMeta)
 	c.placement.ApplyToPodSpec(&podSpec.Spec)
 
 	replicas := int32(1)
-	if len(c.annotations) == 0 {
-		prometheusAnnotations := map[string]string{
-			"prometheus.io/scrape": "true",
-			"prometheus.io/port":   strconv.Itoa(metricsPort),
-		}
-		podSpec.ObjectMeta.Annotations = prometheusAnnotations
-	}
+
 	d := &apps.Deployment{
 		ObjectMeta: metav1.ObjectMeta{
 			Name:      mgrConfig.ResourceName,
@@ -329,6 +325,19 @@ func (c *Cluster) getPodLabels(daemonName string) map[string]string {
 	return labels
 }
 
+func (c *Cluster) applyPrometheusAnnotations(objectMeta *metav1.ObjectMeta) error {
+	if len(c.annotations) == 0 {
+		t := rookalpha.Annotations{
+			"prometheus.io/scrape": "true",
+			"prometheus.io/port":   strconv.Itoa(metricsPort),
+		}
+
+		t.ApplyToObjectMeta(objectMeta)
+	}
+
+	return nil
+}
+
 func (c *Cluster) cephMgrOrchestratorModuleEnvs() []v1.EnvVar {
 	operatorNamespace := os.Getenv(k8sutil.PodNamespaceEnvVar)
 	envVars := []v1.EnvVar{
diff --git a/pkg/operator/ceph/cluster/mgr/spec_test.go b/pkg/operator/ceph/cluster/mgr/spec_test.go
index b42d2f50b..8bb940d16 100644
--- a/pkg/operator/ceph/cluster/mgr/spec_test.go
+++ b/pkg/operator/ceph/cluster/mgr/spec_test.go
@@ -210,3 +210,51 @@ func TestHttpBindFix(t *testing.T) {
 			len(d.Spec.Template.Spec.InitContainers))
 	}
 }
+
+func TestApplyPrometheusAnnotations(t *testing.T) {
+	c := New(
+		&cephconfig.ClusterInfo{FSID: "myfsid"},
+		&clusterd.Context{Clientset: optest.New(1)},
+		"ns",
+		"myversion",
+		cephv1.CephVersionSpec{},
+		rookalpha.Placement{},
+		rookalpha.Annotations{},
+		cephv1.NetworkSpec{},
+		cephv1.DashboardSpec{},
+		cephv1.MonitoringSpec{},
+		cephv1.MgrSpec{},
+		v1.ResourceRequirements{},
+		metav1.OwnerReference{},
+		"/var/lib/rook/",
+		false,
+		false,
+	)
+
+	mgrTestConfig := mgrConfig{
+		DaemonID:      "a",
+		ResourceName:  "rook-ceph-mgr-a",
+		DashboardPort: 1234,
+		DataPathMap:   config.NewStatelessDaemonDataPathMap(config.MgrType, "a", "rook-ceph", "/var/lib/rook/"),
+	}
+
+	d := c.makeDeployment(&mgrTestConfig)
+
+	// Test without annotations
+	c.applyPrometheusAnnotations(&d.ObjectMeta)
+	assert.Equal(t, 2, len(d.ObjectMeta.Annotations))
+
+	// Test with existing annotations
+	// applyPrometheusAnnotations() shouldn't do anything
+	// re-initialize "d"
+	d = c.makeDeployment(&mgrTestConfig)
+
+	fakeAnnotations := rookalpha.Annotations{
+		"foo.io/bar": "foobar",
+	}
+	c.annotations = fakeAnnotations
+
+	c.applyPrometheusAnnotations(&d.ObjectMeta)
+	assert.Equal(t, 1, len(c.annotations))
+	assert.Equal(t, 0, len(d.ObjectMeta.Annotations))
+}