diff --git a/solr/CHANGES.txt b/solr/CHANGES.txt
index 6cd52911487..0b246664fe4 100644
--- a/solr/CHANGES.txt
+++ b/solr/CHANGES.txt
@@ -202,6 +202,9 @@ Other Changes
   refactoring also fixes a bug whereby PointFields were not using DocValues for range queries for
   indexed=false, docValues=true fields. (Ishan Chattopadhyaya, Tomás Fernández Löbbe)
 
+* SOLR-9890: factor out ShardResultTransformerUtils.[un]marshSortValue methods
+  (Judith Silverman, Christine Poerschke)
+
 ==================  6.4.1 ==================
 
 Consult the LUCENE_CHANGES.txt file for additional, low level, changes in this release.
diff --git a/solr/core/src/java/org/apache/solr/search/grouping/distributed/shardresultserializer/SearchGroupsResultTransformer.java b/solr/core/src/java/org/apache/solr/search/grouping/distributed/shardresultserializer/SearchGroupsResultTransformer.java
index 213414a37ec..c5c1e811970 100644
--- a/solr/core/src/java/org/apache/solr/search/grouping/distributed/shardresultserializer/SearchGroupsResultTransformer.java
+++ b/solr/core/src/java/org/apache/solr/search/grouping/distributed/shardresultserializer/SearchGroupsResultTransformer.java
@@ -20,7 +20,6 @@ import org.apache.lucene.search.Sort;
 import org.apache.lucene.search.grouping.SearchGroup;
 import org.apache.lucene.util.BytesRef;
 import org.apache.solr.common.util.NamedList;
-import org.apache.solr.schema.FieldType;
 import org.apache.solr.schema.SchemaField;
 import org.apache.solr.search.SolrIndexSearcher;
 import org.apache.solr.search.grouping.Command;
@@ -90,12 +89,7 @@ public class SearchGroupsResultTransformer implements ShardResultTransformer<Lis
           searchGroup.sortValues = rawSearchGroup.getValue().toArray(new Comparable[rawSearchGroup.getValue().size()]);
           for (int i = 0; i < searchGroup.sortValues.length; i++) {
             SchemaField field = groupSort.getSort()[i].getField() != null ? searcher.getSchema().getFieldOrNull(groupSort.getSort()[i].getField()) : null;
-            if (field != null) {
-              FieldType fieldType = field.getType();
-              if (searchGroup.sortValues[i] != null) {
-                searchGroup.sortValues[i] = fieldType.unmarshalSortValue(searchGroup.sortValues[i]);
-              }
-            }
+            searchGroup.sortValues[i] = ShardResultTransformerUtils.unmarshalSortValue(searchGroup.sortValues[i], field);
           }
           searchGroups.add(searchGroup);
         }
@@ -115,13 +109,7 @@ public class SearchGroupsResultTransformer implements ShardResultTransformer<Lis
       for (int i = 0; i < searchGroup.sortValues.length; i++) {
         Object sortValue = searchGroup.sortValues[i];
         SchemaField field = groupSort.getSort()[i].getField() != null ? searcher.getSchema().getFieldOrNull(groupSort.getSort()[i].getField()) : null;
-        if (field != null) {
-          FieldType fieldType = field.getType();
-          if (sortValue != null) {
-            sortValue = fieldType.marshalSortValue(sortValue);
-          }
-        }
-        convertedSortValues[i] = sortValue;
+        convertedSortValues[i] = ShardResultTransformerUtils.marshalSortValue(sortValue, field);
       }
       String groupValue = searchGroup.groupValue != null ? searchGroup.groupValue.utf8ToString() : null;
       result.add(groupValue, convertedSortValues);
diff --git a/solr/core/src/java/org/apache/solr/search/grouping/distributed/shardresultserializer/ShardResultTransformerUtils.java b/solr/core/src/java/org/apache/solr/search/grouping/distributed/shardresultserializer/ShardResultTransformerUtils.java
new file mode 100644
index 00000000000..df0604c5b5c
--- /dev/null
+++ b/solr/core/src/java/org/apache/solr/search/grouping/distributed/shardresultserializer/ShardResultTransformerUtils.java
@@ -0,0 +1,51 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.solr.search.grouping.distributed.shardresultserializer;
+
+import org.apache.solr.schema.FieldType;
+import org.apache.solr.schema.SchemaField;
+
+/**
+ * Utility functions used by implementations of the {@link ShardResultTransformer} interface.
+ *
+ * @lucene.experimental
+ */
+class ShardResultTransformerUtils {
+
+  static Object marshalSortValue(Object originalSortValue, SchemaField schemaField) {
+    return marshalOrUnmarshalSortValue(originalSortValue, schemaField, true);
+  }
+
+  static Object unmarshalSortValue(Object originalSortValue, SchemaField schemaField) {
+    return marshalOrUnmarshalSortValue(originalSortValue, schemaField, false);
+  }
+
+  private static Object marshalOrUnmarshalSortValue(Object originalSortValue, SchemaField schemaField,
+      boolean marshal) {
+    if (originalSortValue != null && schemaField != null) {
+      final FieldType fieldType = schemaField.getType();
+      if (marshal) {
+        return fieldType.marshalSortValue(originalSortValue);
+      } else {
+        return fieldType.unmarshalSortValue(originalSortValue);
+      }
+    } else {
+      return originalSortValue;
+    }
+  }
+
+}
diff --git a/solr/core/src/java/org/apache/solr/search/grouping/distributed/shardresultserializer/TopGroupsResultTransformer.java b/solr/core/src/java/org/apache/solr/search/grouping/distributed/shardresultserializer/TopGroupsResultTransformer.java
index 37e837e664e..3ff87bd83ed 100644
--- a/solr/core/src/java/org/apache/solr/search/grouping/distributed/shardresultserializer/TopGroupsResultTransformer.java
+++ b/solr/core/src/java/org/apache/solr/search/grouping/distributed/shardresultserializer/TopGroupsResultTransformer.java
@@ -174,12 +174,7 @@ public class TopGroupsResultTransformer implements ShardResultTransformer<List<C
         for (int k = 0; k < sortValues.length; k++) {
           SchemaField field = groupSort.getSort()[k].getField() != null
               ? schema.getFieldOrNull(groupSort.getSort()[k].getField()) : null;
-          if (field != null) {
-            FieldType fieldType = field.getType();
-            if (sortValues[k] != null) {
-              sortValues[k] = fieldType.unmarshalSortValue(sortValues[k]);
-            }
-          }
+          sortValues[k] = ShardResultTransformerUtils.unmarshalSortValue(sortValues[k], field);
         }
       } else {
         log.debug("doc {} has null 'sortValues'", document);
@@ -277,13 +272,7 @@ public class TopGroupsResultTransformer implements ShardResultTransformer<List<C
         Sort groupSort = rb.getGroupingSpec().getGroupSort();
         SchemaField field = groupSort.getSort()[j].getField() != null
                           ? schema.getFieldOrNull(groupSort.getSort()[j].getField()) : null;
-        if (field != null) {
-          FieldType fieldType = field.getType();
-          if (sortValue != null) {
-            sortValue = fieldType.marshalSortValue(sortValue);
-          }
-        }
-        convertedSortValues[j] = sortValue;
+        convertedSortValues[j] = ShardResultTransformerUtils.marshalSortValue(sortValue, field);
       }
       document.add("sortValues", convertedSortValues);
     }