diff --git a/xds/internal/resolver/serviceconfig.go b/xds/internal/resolver/serviceconfig.go
index 6ae1f42169a..c65ce8c7b7c 100644
--- a/xds/internal/resolver/serviceconfig.go
+++ b/xds/internal/resolver/serviceconfig.go
@@ -45,8 +45,10 @@ import (
 )
 
 const (
-	cdsName               = "cds_experimental"
-	xdsClusterManagerName = "xds_cluster_manager_experimental"
+	cdsName                      = "cds_experimental"
+	xdsClusterManagerName        = "xds_cluster_manager_experimental"
+	clusterPrefix                = "cluster:"
+	clusterSpecifierPluginPrefix = "cluster_specifier_plugin:"
 )
 
 type serviceConfig struct {
@@ -180,7 +182,6 @@ func (cs *configSelector) SelectConfig(rpcInfo iresolver.RPCInfo) (*iresolver.RP
 		return nil, status.Errorf(codes.Internal, "error retrieving cluster for match: %v (%T)", cluster, cluster)
 	}
 
-
 	// Add a ref to the selected cluster, as this RPC needs this cluster until
 	// it is committed.
 	ref := &cs.clusters[cluster.name].refCount
@@ -373,32 +374,19 @@ func (r *xdsResolver) newConfigSelector(su serviceUpdate) (*configSelector, erro
 	for i, rt := range su.virtualHost.Routes {
 		clusters := newWRR()
 		if rt.ClusterSpecifierPlugin != "" {
+			clusterName := clusterSpecifierPluginPrefix + rt.ClusterSpecifierPlugin
 			clusters.Add(&routeCluster{
-				name:                     "cluster:" + rt.ClusterSpecifierPlugin,
+				name: clusterName,
 			}, 1)
-
-			ci := r.activeClusters["cluster_specifier_plugin:" + rt.ClusterSpecifierPlugin]
-			if ci == nil {
-				ci = &clusterInfo{refCount: 0}
-				r.activeClusters["cluster_specifier_plugin:" + rt.ClusterSpecifierPlugin] = ci
-			}
-			cs.clusters["cluster_specifier_plugin:" + rt.ClusterSpecifierPlugin] = ci
+			r.initializeCluster(clusterName, cs)
 		} else {
 			for cluster, wc := range rt.WeightedClusters {
+				clusterName := clusterPrefix + cluster
 				clusters.Add(&routeCluster{
-					name:                     "cluster:" + cluster,
+					name:                     clusterName,
 					httpFilterConfigOverride: wc.HTTPFilterConfigOverride,
 				}, int64(wc.Weight))
-
-				// Initialize entries in cs.clusters map, creating entries in
-				// r.activeClusters as necessary.  Set to zero as they will be
-				// incremented by incRefs.
-				ci := r.activeClusters["cluster:" + cluster]
-				if ci == nil {
-					ci = &clusterInfo{refCount: 0}
-					r.activeClusters["cluster:" + cluster] = ci
-				}
-				cs.clusters["cluster:" + cluster] = ci
+				r.initializeCluster(clusterName, cs)
 			}
 		}
 		cs.routes[i].clusters = clusters
@@ -429,6 +417,18 @@ func (r *xdsResolver) newConfigSelector(su serviceUpdate) (*configSelector, erro
 	return cs, nil
 }
 
+// initializeCluster initializes entries in cs.clusters map, creating entries in
+// r.activeClusters as necessary.  Any created entries will be set to zero as
+// they will be incremented by incRefs.
+func (r *xdsResolver) initializeCluster(clusterName string, cs *configSelector) {
+	ci := r.activeClusters[clusterName]
+	if ci == nil {
+		ci = &clusterInfo{refCount: 0}
+		r.activeClusters[clusterName] = ci
+	}
+	cs.clusters[clusterName] = ci
+}
+
 type clusterInfo struct {
 	// number of references to this cluster; accessed atomically
 	refCount int32