diff -u b/core/includes/tablesort.inc b/core/includes/tablesort.inc
--- b/core/includes/tablesort.inc
+++ b/core/includes/tablesort.inc
@@ -21,7 +21,7 @@
  * @see https://www.drupal.org/node/3009182
  */
 function tablesort_init($header) {
-  @trigger_error(__FUNCTION__ . ' is deprecated in Drupal 8.7.x and will be removed before Drupal 9.0.0. Instead, get a TableSort utility injected into your service from the container and call init() on it. For example, $table_sort->init($header). See https://www.drupal.org/node/3009182', E_USER_DEPRECATED);
+  @trigger_error(__FUNCTION__ . '() is deprecated in Drupal 8.7.x and will be removed before Drupal 9.0.0. Instead, get a TableSort utility injected into your service from the container and call init() on it. For example, $table_sort->init($header). See https://www.drupal.org/node/3009182', E_USER_DEPRECATED);
   return \Drupal::service('table_sort')->init($header);
 }
 
@@ -49,7 +49,7 @@
  * @see https://www.drupal.org/node/3009182
  */
 function tablesort_header(&$cell_content, array &$cell_attributes, array $header, array $ts) {
-  @trigger_error(__FUNCTION__ . ' is deprecated in Drupal 8.7.x and will be removed before Drupal 9.0.0. Instead, get a TableSort utility injected into your service from the container and call header() on it. For example, $table_sort->header($cell_content, $cell_attributes, $header, $ts). See https://www.drupal.org/node/3009182', E_USER_DEPRECATED);
+  @trigger_error(__FUNCTION__ . '() is deprecated in Drupal 8.7.x and will be removed before Drupal 9.0.0. Instead, get a TableSort utility injected into your service from the container and call header() on it. For example, $table_sort->header($cell_content, $cell_attributes, $header, $ts). See https://www.drupal.org/node/3009182', E_USER_DEPRECATED);
   \Drupal::service('table_sort')->header($cell_content, $cell_attributes, $header, $ts);
 }
 
@@ -65,11 +65,11 @@
  *   container and call getQueryParameters() on it. For example,
  *   $table_sort->getQueryParameters();
  *
- * @see \Drupal\Core\Utility\TableSortInterface::getQueryParameters()
+ * @see \Drupal\Core\Utility\TableSort::getQueryParameters()
  * @see https://www.drupal.org/node/3009182
  */
 function tablesort_get_query_parameters() {
-  @trigger_error(__FUNCTION__ . ' is deprecated in Drupal 8.7.x and will be removed before Drupal 9.0.0. Instead, get a TableSort utility injected into your service from the container and call getQueryParameters() on it. For example, $table_sort->getQueryParameters(). See https://www.drupal.org/node/3009182', E_USER_DEPRECATED);
+  @trigger_error(__FUNCTION__ . '() is deprecated in Drupal 8.7.x and will be removed before Drupal 9.0.0. Instead, get a TableSort utility injected into your service from the container and call getQueryParameters() on it. For example, $table_sort->getQueryParameters(). See https://www.drupal.org/node/3009182', E_USER_DEPRECATED);
   return \Drupal::service('table_sort')->getQueryParameters();
 }
 
@@ -93,7 +93,7 @@
  * @see https://www.drupal.org/node/3009182
  */
 function tablesort_get_order($headers) {
-  @trigger_error(__FUNCTION__ . ' is deprecated in Drupal 8.7.x and will be removed before Drupal 9.0.0. Instead, get a TableSort utility injected into your service from the container and call getOrder() on it. For example, $table_sort->getOrder($headers). See https://www.drupal.org/node/3009182', E_USER_DEPRECATED);
+  @trigger_error(__FUNCTION__ . '() is deprecated in Drupal 8.7.x and will be removed before Drupal 9.0.0. Instead, get a TableSort utility injected into your service from the container and call getOrder() on it. For example, $table_sort->getOrder($headers). See https://www.drupal.org/node/3009182', E_USER_DEPRECATED);
   return \Drupal::service('table_sort')->getOrder($headers);
 }
 
@@ -116,5 +116,5 @@
  */
 function tablesort_get_sort($headers) {
-  @trigger_error(__FUNCTION__ . ' is deprecated in Drupal 8.7.x and will be removed before Drupal 9.0.0. Instead, get a TableSort utility injected into your service from the container and call getSort() on it. For example, $table_sort->getSort($headers). See https://www.drupal.org/node/3009182', E_USER_DEPRECATED);
+  @trigger_error(__FUNCTION__ . '() is deprecated in Drupal 8.7.x and will be removed before Drupal 9.0.0. Instead, get a TableSort utility injected into your service from the container and call getSort() on it. For example, $table_sort->getSort($headers). See https://www.drupal.org/node/3009182', E_USER_DEPRECATED);
   return \Drupal::service('table_sort')->getSort($headers);
 }
diff -u b/core/lib/Drupal/Core/Utility/TableSort.php b/core/lib/Drupal/Core/Utility/TableSort.php
--- b/core/lib/Drupal/Core/Utility/TableSort.php
+++ b/core/lib/Drupal/Core/Utility/TableSort.php
@@ -58,10 +58,7 @@
    *   The current request object.
    */
   protected function request(Request $request = NULL) {
-    if ($request) {
-      return $request;
-    }
-    return $this->requestStack->getCurrentRequest();
+    return $request ?: $this->requestStack->getCurrentRequest();
   }
 
   /**
@@ -116,13 +113,6 @@
   /**
    * {@inheritdoc}
    */
-  public function getQueryParameters(Request $request = NULL) {
-    return UrlHelper::filterQueryParameters($this->request($request)->query->all(), ['sort', 'order']);
-  }
-
-  /**
-   * {@inheritdoc}
-   */
   public function getOrder(array $headers, Request $request = NULL) {
     $order = $this->request($request)->query->get('order', '');
     foreach ($headers as $header) {
@@ -172,2 +162,16 @@
 
+  /**
+   * Composes a URL query parameter array for table sorting links.
+   *
+   * @param \Symfony\Component\HttpFoundation\Request|null $request
+   *   A current request (optional).
+   *
+   * @return array
+   *   A URL query parameter array that consists of all components of the
+   *   current page request except for those pertaining to table sorting.
+   */
+  public function getQueryParameters(Request $request = NULL) {
+    return UrlHelper::filterQueryParameters($this->request($request)->query->all(), ['sort', 'order']);
+  }
+
 }
diff -u b/core/lib/Drupal/Core/Utility/TableSortInterface.php b/core/lib/Drupal/Core/Utility/TableSortInterface.php
--- b/core/lib/Drupal/Core/Utility/TableSortInterface.php
+++ b/core/lib/Drupal/Core/Utility/TableSortInterface.php
@@ -48,18 +48,6 @@
   public function header(&$cell_content, array &$cell_attributes, array $header, array $context);
 
   /**
-   * Composes a URL query parameter array for table sorting links.
-   *
-   * @param \Symfony\Component\HttpFoundation\Request|null $request
-   *   A current request (optional).
-   *
-   * @return array
-   *   A URL query parameter array that consists of all components of the
-   *   current page request except for those pertaining to table sorting.
-   */
-  public function getQueryParameters(Request $request = NULL);
-
-  /**
    * Determines the current sort criterion.
    *
    * @param array $headers
only in patch2:
unchanged:
--- /dev/null
+++ b/core/tests/Drupal/KernelTests/Core/Theme/TableSortLegacyTest.php
@@ -0,0 +1,75 @@
+<?php
+
+namespace Drupal\KernelTests\Core\Theme;
+
+use Drupal\Core\Utility\TableSortInterface;
+use Drupal\KernelTests\KernelTestBase;
+
+/**
+ * Deprecation tests cases for the tablesort.inc file functions.
+ *
+ * @package Drupal\KernelTests\Core\Theme
+ *
+ * @group legacy
+ */
+class TableSortLegacyTest extends KernelTestBase {
+
+  /**
+   * Tests deprecation of the tablesort_init() function.
+   *
+   * @expectedDeprecation tablesort_init() is deprecated in Drupal 8.7.x and will be removed before Drupal 9.0.0. Instead, get a TableSort utility injected into your service from the container and call init() on it. For example, $table_sort->init($header). See https://www.drupal.org/node/3009182
+   */
+  public function testInit() {
+    $context = tablesort_init([]);
+    $this->assertArrayHasKey('query', $context);
+    $this->assertArrayHasKey('sort', $context);
+  }
+
+  /**
+   * Tests deprecation of the tablesort_header() function.
+   *
+   * @expectedDeprecation tablesort_header() is deprecated in Drupal 8.7.x and will be removed before Drupal 9.0.0. Instead, get a TableSort utility injected into your service from the container and call header() on it. For example, $table_sort->header($cell_content, $cell_attributes, $header, $ts). See https://www.drupal.org/node/3009182
+   */
+  public function testHeader() {
+    $cell_content = '';
+    $cell_attributes = [];
+    tablesort_header($cell_content, $cell_attributes, [], []);
+    $this->assertEquals('', $cell_content);
+  }
+
+  /**
+   * Tests deprecation of the tablesort_get_query_parameters() function.
+   *
+   * @expectedDeprecation tablesort_get_query_parameters() is deprecated in Drupal 8.7.x and will be removed before Drupal 9.0.0. Instead, get a TableSort utility injected into your service from the container and call getQueryParameters() on it. For example, $table_sort->getQueryParameters(). See https://www.drupal.org/node/3009182
+   */
+  public function testQueryParameters() {
+    $parameters = tablesort_get_query_parameters();
+    $this->assertArrayNotHasKey('sort', $parameters);
+    $this->assertArrayNotHasKey('order', $parameters);
+  }
+
+  /**
+   * Tests deprecation of the tablesort_get_order() function.
+   *
+   * @expectedDeprecation tablesort_get_order() is deprecated in Drupal 8.7.x and will be removed before Drupal 9.0.0. Instead, get a TableSort utility injected into your service from the container and call getOrder() on it. For example, $table_sort->getOrder($headers). See https://www.drupal.org/node/3009182
+   */
+  public function testOrder() {
+    $this->assertEquals(
+      [
+        'name' => NULL,
+        'sql' => NULL,
+      ],
+      tablesort_get_order([])
+    );
+  }
+
+  /**
+   * Tests deprecation of the tablesort_get_sort() function.
+   *
+   * @expectedDeprecation tablesort_get_sort() is deprecated in Drupal 8.7.x and will be removed before Drupal 9.0.0. Instead, get a TableSort utility injected into your service from the container and call getSort() on it. For example, $table_sort->getSort($headers). See https://www.drupal.org/node/3009182
+   */
+  public function testSort() {
+    $this->assertEquals(TableSortInterface::ASC, tablesort_get_sort([]));
+  }
+
+}