diff --git a/pkg/fleet-manager/clusters.go b/pkg/fleet-manager/clusters.go
index cc248afdc..78df3ed30 100644
--- a/pkg/fleet-manager/clusters.go
+++ b/pkg/fleet-manager/clusters.go
@@ -70,7 +70,7 @@ func (f *FleetManager) reconcileClusters(ctx context.Context, fleet *fleetapi.Fl
 	for _, cluster := range fleet.Spec.Clusters {
 		// cluster namespace can be not set, always use fleet namespace as a fleet can only include clusters in the same namespace.
 		clusterKey := types.NamespacedName{Name: cluster.Name, Namespace: fleet.Namespace}
-		currentCluster, err := f.getFleetClusterInterface(ctx, cluster.Kind, clusterKey)
+		currentCluster, err := getFleetClusterInterface(ctx, f.Client, cluster.Kind, clusterKey)
 		if err != nil {
 			if !apierrors.IsNotFound(err) {
 				log.Error(err, "unable to fetch cluster", "cluster", clusterKey, "kind", cluster.Kind)
@@ -190,7 +190,7 @@ func (f *FleetManager) reconcileClustersOnDelete(ctx context.Context, fleet *fle
 	for _, cluster := range fleet.Spec.Clusters {
 		// cluster namespace can be not set, always use fleet namespace as a fleet can only include clusters in the same namespace.
 		clusterKey := types.NamespacedName{Name: cluster.Name, Namespace: fleet.Namespace}
-		currentCluster, err := f.getFleetClusterInterface(ctx, cluster.Kind, clusterKey)
+		currentCluster, err := getFleetClusterInterface(ctx, f.Client, cluster.Kind, clusterKey)
 		if err != nil {
 			if !apierrors.IsNotFound(err) {
 				log.Error(err, "unable to fetch cluster", "cluster", clusterKey)
diff --git a/pkg/fleet-manager/fleet.go b/pkg/fleet-manager/fleet.go
index 389602ff7..e27973de3 100644
--- a/pkg/fleet-manager/fleet.go
+++ b/pkg/fleet-manager/fleet.go
@@ -166,7 +166,7 @@ func (f *FleetManager) reconcile(ctx context.Context, fleet *fleetapi.Fleet) (ct
 		return res, err
 	}
 
-	fleetClusters, err := f.buildFleetClusters(ctx, fleet)
+	fleetClusters, err := buildFleetClusters(ctx, f.Client, fleet)
 	if err != nil {
 		return ctrl.Result{}, fmt.Errorf("failed to build cluster clients: %w", err)
 	}
diff --git a/pkg/fleet-manager/fleet_cluster.go b/pkg/fleet-manager/fleet_cluster.go
index b4fe7fd13..7c87ae3eb 100644
--- a/pkg/fleet-manager/fleet_cluster.go
+++ b/pkg/fleet-manager/fleet_cluster.go
@@ -24,6 +24,7 @@ import (
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/client-go/tools/clientcmd"
 	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/client"
 
 	clusterv1alpha1 "kurator.dev/kurator/pkg/apis/cluster/v1alpha1"
 	fleetapi "kurator.dev/kurator/pkg/apis/fleet/v1alpha1"
@@ -41,13 +42,13 @@ type ClusterKey struct {
 	Name string
 }
 
-func (f *FleetManager) buildFleetClusters(ctx context.Context, fleet *fleetapi.Fleet) (map[ClusterKey]*fleetCluster, error) {
+func buildFleetClusters(ctx context.Context, client client.Client, fleet *fleetapi.Fleet) (map[ClusterKey]*fleetCluster, error) {
 	log := ctrl.LoggerFrom(ctx)
 
 	res := make(map[ClusterKey]*fleetCluster, len(fleet.Spec.Clusters))
-	for _, c := range fleet.Spec.Clusters {
-		clusterKey := types.NamespacedName{Namespace: fleet.Namespace, Name: c.Name}
-		clusterInterface, err := f.getFleetClusterInterface(ctx, c.Kind, clusterKey)
+	for _, cluster := range fleet.Spec.Clusters {
+		clusterKey := types.NamespacedName{Namespace: fleet.Namespace, Name: cluster.Name}
+		clusterInterface, err := getFleetClusterInterface(ctx, client, cluster.Kind, clusterKey)
 		// TODO: should we make it work
 		if err != nil {
 			return nil, err
@@ -58,11 +59,11 @@ func (f *FleetManager) buildFleetClusters(ctx context.Context, fleet *fleetapi.F
 			continue
 		}
 
-		kclient, err := f.clientForCluster(fleet.Namespace, clusterInterface)
+		kclient, err := clientForCluster(client, fleet.Namespace, clusterInterface)
 		if err != nil {
 			return nil, err
 		}
-		res[ClusterKey{Kind: c.Kind, Name: c.Name}] = &fleetCluster{
+		res[ClusterKey{Kind: cluster.Kind, Name: cluster.Name}] = &fleetCluster{
 			Secret:    clusterInterface.GetSecretName(),
 			SecretKey: clusterInterface.GetSecretKey(),
 			client:    kclient,
@@ -72,17 +73,17 @@ func (f *FleetManager) buildFleetClusters(ctx context.Context, fleet *fleetapi.F
 	return res, nil
 }
 
-func (f *FleetManager) getFleetClusterInterface(ctx context.Context, kind string, nn types.NamespacedName) (ClusterInterface, error) {
+func getFleetClusterInterface(ctx context.Context, client client.Client, kind string, nn types.NamespacedName) (ClusterInterface, error) {
 	switch kind {
 	case ClusterKind, "":
 		cluster := &clusterv1alpha1.Cluster{}
-		if err := f.Get(ctx, nn, cluster); err != nil {
+		if err := client.Get(ctx, nn, cluster); err != nil {
 			return nil, err
 		}
 		return cluster, nil
 	case AttachedClusterKind:
 		attachedCluster := &clusterv1alpha1.AttachedCluster{}
-		if err := f.Get(ctx, nn, attachedCluster); err != nil {
+		if err := client.Get(ctx, nn, attachedCluster); err != nil {
 			return nil, err
 		}
 		return attachedCluster, nil
@@ -91,10 +92,10 @@ func (f *FleetManager) getFleetClusterInterface(ctx context.Context, kind string
 	}
 }
 
-func (f *FleetManager) clientForCluster(ns string, cluster ClusterInterface) (*kclient.Client, error) {
+func clientForCluster(client client.Client, ns string, cluster ClusterInterface) (*kclient.Client, error) {
 	secret := &corev1.Secret{}
 	nn := types.NamespacedName{Namespace: ns, Name: cluster.GetSecretName()}
-	if err := f.Client.Get(context.Background(), nn, secret); err != nil {
+	if err := client.Get(context.Background(), nn, secret); err != nil {
 		return nil, err
 	}