diff --git a/pkg/estimator/client/general.go b/pkg/estimator/client/general.go
index 6023c89f528a..46d3c40d92ce 100644
--- a/pkg/estimator/client/general.go
+++ b/pkg/estimator/client/general.go
@@ -54,7 +54,8 @@ func (ge *GeneralEstimator) MaxAvailableReplicas(_ context.Context, clusters []*
 }
 
 func (ge *GeneralEstimator) maxAvailableReplicas(cluster *clusterv1alpha1.Cluster, replicaRequirements *workv1alpha2.ReplicaRequirements) int32 {
-	resourceSummary := cluster.Status.ResourceSummary
+	//Note: resourceSummary must be deep-copied before using in the function to avoid modifying the original data structure.
+	resourceSummary := cluster.Status.ResourceSummary.DeepCopy()
 	if resourceSummary == nil {
 		return 0
 	}