diff --git a/pytorch_lightning/utilities/apply_func.py b/pytorch_lightning/utilities/apply_func.py
index 947b00d7ab61e..ecf638c2beb90 100644
--- a/pytorch_lightning/utilities/apply_func.py
+++ b/pytorch_lightning/utilities/apply_func.py
@@ -126,24 +126,25 @@ def apply_to_collection(
         memo = {}
         for field in dataclasses.fields(data):
             field_value = getattr(data, field.name)
-            fields[field.name] = field_value
+            fields[field.name] = (field_value, field.init)
             memo[id(field_value)] = field_value
         result = deepcopy(data, memo=memo)
         # apply function to each field
-        for field_name, field_value in fields.items():
-            v = apply_to_collection(
-                field_value,
-                dtype,
-                function,
-                *args,
-                wrong_dtype=wrong_dtype,
-                include_none=include_none,
-                **kwargs,
-            )
-            if include_none or v is not None:
-                setattr(result, field_name, v)
-            else:  # retain old value
-                setattr(result, field_name, getattr(data, field_name))
+        for field_name, (field_value, field_init) in fields.items():
+            if field_init:
+                v = apply_to_collection(
+                    field_value,
+                    dtype,
+                    function,
+                    *args,
+                    wrong_dtype=wrong_dtype,
+                    include_none=include_none,
+                    **kwargs,
+                )
+                if include_none or v is not None:
+                    setattr(result, field_name, v)
+                else:  # retain old value
+                    setattr(result, field_name, getattr(data, field_name))
         return result
 
     # data is neither of dtype, nor a collection