diff -u b/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
--- b/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -10,13 +10,13 @@
 use Drupal\Component\Render\FormattableMarkup;
 use Drupal\Component\Utility\Unicode;
 use Drupal\Core\Config\BootstrapConfigStorageFactory;
-use Drupal\Core\Database\Database;
 use Drupal\Core\Installer\InstallerKernel;
 use Drupal\Core\Logger\RfcLogLevel;
 use Drupal\Core\Test\TestDatabase;
 use Drupal\Core\Site\Settings;
 use Drupal\Core\Utility\Error;
 use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Drupal\Core\Extension\ExtensionDiscovery;
 use Symfony\Component\DependencyInjection\Exception\ServiceNotFoundException;
 /**
  *
@@ -142,14 +142,9 @@
 /**
  * Regular expression to match PHP function names.
  *
- * @deprecated in drupal:8.8.0 and is removed from drupal:9.0.0. Use
- *   Database::DRIVER_NAME_PATTERN instead.
- *
- * @see https://www.drupal.org/node/2936107
- *
  * @see http://php.net/manual/language.functions.php
  */
-const DRUPAL_PHP_FUNCTION_PATTERN = Database::DRIVER_NAME_PATTERN;
+const DRUPAL_PHP_FUNCTION_PATTERN = ExtensionDiscovery::PHP_FUNCTION_PATTERN;
 
 /**
  * $config_directories key for active directory.
diff -u b/core/includes/install.inc b/core/includes/install.inc
--- b/core/includes/install.inc
+++ b/core/includes/install.inc
@@ -14,7 +14,6 @@
 use Drupal\Core\File\FileSystemInterface;
 use Drupal\Core\Installer\InstallerKernel;
 use Drupal\Core\Site\Settings;
-use Drupal\Core\Database\Database;
 use Symfony\Component\HttpFoundation\RedirectResponse;
 
 /**
@@ -166,6 +165,6 @@
   $drivers = [];
   // The internal database driver name is any valid PHP identifier.
-  $mask = '/^' . Database::DRIVER_NAME_PATTERN . '$/';
+  $mask = ExtensionDiscovery::PHP_FUNCTION_PATTERN;
   /** @var \Drupal\Core\File\FileSystemInterface $file_system */
   $file_system = \Drupal::service('file_system');
   $files = $file_system->scanDirectory(DRUPAL_ROOT . '/core/lib/Drupal/Core/Database/Driver', $mask, ['recurse' => FALSE]);
reverted:
--- b/core/lib/Drupal/Core/Database/Database.php
+++ a/core/lib/Drupal/Core/Database/Database.php
@@ -34,13 +34,6 @@
    */
   const RETURN_INSERT_ID = 3;
 
-  /**
-   * Regular expression to match driver names.
-   *
-   * @see http://php.net/manual/language.functions.php
-   */
-  const DRIVER_NAME_PATTERN = '[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*';
-
   /**
    * An nested array of all active connections. It is keyed by database name
    * and target.