diff --git chrome/browser/optimization_guide/optimization_guide_keyed_service.cc chrome/browser/optimization_guide/optimization_guide_keyed_service.cc
index bd928f4422f99..f0124ab225b6f 100644
--- chrome/browser/optimization_guide/optimization_guide_keyed_service.cc
+++ chrome/browser/optimization_guide/optimization_guide_keyed_service.cc
@@ -269,7 +269,7 @@ void OptimizationGuideKeyedService::Initialize() {
       MaybeCreatePushNotificationManager(profile),
       optimization_guide_logger_.get());
   base::FilePath model_downloads_dir;
-  if (!profile->IsOffTheRecord()) {
+  if (!profile->IsOffTheRecord() && !profile_path.empty()) {
     // Do not explicitly hand off the model downloads directory to
     // off-the-record profiles. Underneath the hood, this variable is only used
     // in non off-the-record profiles to know where to download the model files
@@ -281,7 +281,7 @@ void OptimizationGuideKeyedService::Initialize() {
 
   prediction_manager_ = std::make_unique<optimization_guide::PredictionManager>(
       prediction_model_and_features_store, url_loader_factory,
-      profile->GetPrefs(), profile->IsOffTheRecord(),
+      profile->GetPrefs(), /*is_off_the_record=*/model_downloads_dir.empty(),
       g_browser_process->GetApplicationLocale(), model_downloads_dir,
       optimization_guide_logger_.get(),
       base::BindOnce(