diff --git a/data-prepper-plugins/mutate-event-processors/src/main/java/org/opensearch/dataprepper/plugins/processor/mutateevent/RenameKeyProcessor.java b/data-prepper-plugins/mutate-event-processors/src/main/java/org/opensearch/dataprepper/plugins/processor/mutateevent/RenameKeyProcessor.java
index b4bddc6acb..6699f409cb 100644
--- a/data-prepper-plugins/mutate-event-processors/src/main/java/org/opensearch/dataprepper/plugins/processor/mutateevent/RenameKeyProcessor.java
+++ b/data-prepper-plugins/mutate-event-processors/src/main/java/org/opensearch/dataprepper/plugins/processor/mutateevent/RenameKeyProcessor.java
@@ -47,10 +47,10 @@ public RenameKeyProcessor(final PluginMetrics pluginMetrics, final RenameKeyProc
                                 entry.getRenameWhen()));
             }
             if (entry.getFromKey() == null && entry.getFromKeyPattern() == null) {
-                throw new InvalidPluginConfigurationException("Either from_key or from_key_pattern must be specified. Both cannot be set together.");
+                throw new InvalidPluginConfigurationException("Either from_key or from_key_regex must be specified. ");
             }
             if (entry.getFromKey() != null && entry.getFromKeyPattern()  != null) {
-                throw new InvalidPluginConfigurationException("Only one of from_key or from_key_pattern should be specified.");
+                throw new InvalidPluginConfigurationException("Only one of from_key or from_key_regex should be specified.");
             }
         });
     }
diff --git a/data-prepper-plugins/mutate-event-processors/src/main/java/org/opensearch/dataprepper/plugins/processor/mutateevent/RenameKeyProcessorConfig.java b/data-prepper-plugins/mutate-event-processors/src/main/java/org/opensearch/dataprepper/plugins/processor/mutateevent/RenameKeyProcessorConfig.java
index 74533481fd..af73e21b81 100644
--- a/data-prepper-plugins/mutate-event-processors/src/main/java/org/opensearch/dataprepper/plugins/processor/mutateevent/RenameKeyProcessorConfig.java
+++ b/data-prepper-plugins/mutate-event-processors/src/main/java/org/opensearch/dataprepper/plugins/processor/mutateevent/RenameKeyProcessorConfig.java
@@ -13,6 +13,7 @@
 import jakarta.validation.Valid;
 import jakarta.validation.constraints.NotEmpty;
 import jakarta.validation.constraints.NotNull;
+import org.opensearch.dataprepper.model.annotations.AlsoRequired;
 import org.opensearch.dataprepper.model.annotations.ExampleValues;
 import org.opensearch.dataprepper.model.annotations.ExampleValues.Example;
 import org.opensearch.dataprepper.model.event.EventKey;
@@ -27,13 +28,24 @@
 public class RenameKeyProcessorConfig {
     @JsonPropertyOrder
     public static class Entry {
-        @JsonProperty("from_key")
-        @JsonPropertyDescription("The key of the entry to be renamed.")
+        static  final String FROM_KEY = "from_key";
+        static final String FROM_KEY_REGEX = "from_key_regex";
+        @JsonProperty(defaultValue = FROM_KEY)
+        @JsonPropertyDescription("The key of the entry to be renamed. " +
+                "This field cannot be defined along with <code>from_key_regex</code>.")
+        @AlsoRequired(values = {
+                @AlsoRequired.Required(name = FROM_KEY_REGEX, allowedValues = {"null"})
+        })
         @EventKeyConfiguration({EventKeyFactory.EventAction.GET, EventKeyFactory.EventAction.DELETE})
         private EventKey fromKey;
 
-        @JsonProperty("from_key_regex")
-        @JsonPropertyDescription("The regex pattern of the key of the entry to be renamed.")
+
+        @JsonProperty(defaultValue = FROM_KEY_REGEX)
+        @JsonPropertyDescription("The regex pattern of the key of the entry to be renamed. " +
+                "This field cannot be defined along with <code>from_key</code>.")
+        @AlsoRequired(values = {
+                @AlsoRequired.Required(name = FROM_KEY, allowedValues = {"null"})
+        })
         private String fromKeyRegex;
 
         @NotEmpty