diff --git a/includes/abstracts/abstract-wc-legacy-product.php b/includes/abstracts/abstract-wc-legacy-product.php
index 965346d7b08..731d1265a6c 100644
--- a/includes/abstracts/abstract-wc-legacy-product.php
+++ b/includes/abstracts/abstract-wc-legacy-product.php
@@ -21,6 +21,36 @@ if ( ! defined( 'ABSPATH' ) ) {
  */
 abstract class WC_Abstract_Legacy_Product extends WC_Data {
 
+	/**
+	 * Get and return related products.
+	 * @deprecated 2.7.0 Use wc_get_related_products instead.
+	 */
+	public function get_related( $limit = 5 ) {
+		_deprecated_function( 'WC_Product::get_related', '2.7', 'wc_get_related_products' );
+		return wc_get_related_products( $this->get_id(), $limit );
+	}
+
+	/**
+	 * Retrieves related product terms.
+	 * @deprecated 2.7.0 Use wc_get_product_term_ids instead.
+	 */
+	protected function get_related_terms( $term ) {
+		_deprecated_function( 'WC_Product::get_related_terms', '2.7', 'wc_get_product_term_ids' );
+		return array_merge( array( 0 ), wc_get_product_term_ids( $this->get_id(), $term ) );
+	}
+
+	/**
+	 * Builds the related posts query.
+	 * @deprecated 2.7.0 Use wc_get_related_products_query instead.
+	 */
+	protected function build_related_query( $cats_array, $tags_array, $exclude_ids, $limit ) {
+		_deprecated_function( 'WC_Product::build_related_query', '2.7', 'wc_get_related_products_query' );
+		return wc_get_related_products_query( $cats_array, $tags_array, $exclude_ids, $limit );
+	}
+
+
+
+
 	/**
 	 * The product's type (simple, variable etc).
 	 *
diff --git a/includes/abstracts/abstract-wc-product.php b/includes/abstracts/abstract-wc-product.php
index 97ce0e021a0..d2be0d2e460 100644
--- a/includes/abstracts/abstract-wc-product.php
+++ b/includes/abstracts/abstract-wc-product.php
@@ -2076,57 +2076,6 @@ class WC_Product extends WC_Abstract_Legacy_Product {
 		return absint( $this->shipping_class_id );
 	}
 
-	/**
-	 * Get and return related products.
-	 *
-	 * Notes:
-	 * 	- Results are cached in a transient for faster queries.
-	 *  - To make results appear random, we query and extra 10 products and shuffle them.
-	 *  - To ensure we always have enough results, it will check $limit before returning the cached result, if not recalc.
-	 *  - This used to rely on transient version to invalidate cache, but to avoid multiple transients we now just expire daily.
-	 *  	This means if a related product is edited and no longer related, it won't be removed for 24 hours. Acceptable trade-off for performance.
-	 *  - Saving a product will flush caches for that product.
-	 *
-	 * @param int $limit (default: 5) Should be an integer greater than 0.
-	 * @return array Array of post IDs
-	 */
-	public function get_related( $limit = 5 ) {
-		global $wpdb;
-
-		$transient_name = 'wc_related_' . $this->get_id();
-		$related_posts  = get_transient( $transient_name );
-		$limit          = $limit > 0 ? $limit : 5;
-
-		// We want to query related posts if they are not cached, or we don't have enough
-		if ( false === $related_posts || sizeof( $related_posts ) < $limit ) {
-			// Related products are found from category and tag
-			$tags_array = $this->get_related_terms( 'product_tag' );
-			$cats_array = $this->get_related_terms( 'product_cat' );
-
-			// Don't bother if none are set
-			if ( 1 === sizeof( $cats_array ) && 1 === sizeof( $tags_array ) ) {
-				$related_posts = array();
-			} else {
-				// Sanitize
-				$exclude_ids = array_map( 'absint', array_merge( array( 0, $this->get_id() ), $this->get_upsells() ) );
-
-				// Generate query - but query an extra 10 results to give the appearance of random results
-				$query = $this->build_related_query( $cats_array, $tags_array, $exclude_ids, $limit + 10 );
-
-				// Get the posts
-				$related_posts = $wpdb->get_col( implode( ' ', $query ) );
-			}
-
-			set_transient( $transient_name, $related_posts, DAY_IN_SECONDS );
-		}
-
-		// Randomise the results
-		shuffle( $related_posts );
-
-		// Limit the returned results
-		return array_slice( $related_posts, 0, $limit );
-	}
-
 	/**
 	 * Returns a single product attribute.
 	 *
@@ -2303,84 +2252,6 @@ class WC_Product extends WC_Abstract_Legacy_Product {
 		return sprintf( '%s &ndash; %s', $identifier, $this->get_title() );
 	}
 
-	/**
-	 * Retrieves related product terms.
-	 *
-	 * @param string $term
-	 * @return array
-	 */
-	protected function get_related_terms( $term ) {
-		$terms_array = array( 0 );
-
-		$terms = apply_filters( 'woocommerce_get_related_' . $term . '_terms', wp_get_post_terms( $this->get_id(), $term ), $this->get_id() );
-		foreach ( $terms as $term ) {
-			$terms_array[] = $term->term_id;
-		}
-
-		return array_map( 'absint', $terms_array );
-	}
-
-	/**
-	 * Builds the related posts query.
-	 *
-	 * @param array $cats_array
-	 * @param array $tags_array
-	 * @param array $exclude_ids
-	 * @param int   $limit
-	 * @return string
-	 */
-	protected function build_related_query( $cats_array, $tags_array, $exclude_ids, $limit ) {
-		global $wpdb;
-
-		$limit = absint( $limit );
-
-		$query           = array();
-		$query['fields'] = "SELECT DISTINCT ID FROM {$wpdb->posts} p";
-		$query['join']   = " INNER JOIN {$wpdb->postmeta} pm ON ( pm.post_id = p.ID AND pm.meta_key='_visibility' )";
-		$query['join']  .= " INNER JOIN {$wpdb->term_relationships} tr ON (p.ID = tr.object_id)";
-		$query['join']  .= " INNER JOIN {$wpdb->term_taxonomy} tt ON (tr.term_taxonomy_id = tt.term_taxonomy_id)";
-		$query['join']  .= " INNER JOIN {$wpdb->terms} t ON (t.term_id = tt.term_id)";
-
-		if ( get_option( 'woocommerce_hide_out_of_stock_items' ) === 'yes' ) {
-			$query['join'] .= " INNER JOIN {$wpdb->postmeta} pm2 ON ( pm2.post_id = p.ID AND pm2.meta_key='_stock_status' )";
-		}
-
-		$query['where']  = " WHERE 1=1";
-		$query['where'] .= " AND p.post_status = 'publish'";
-		$query['where'] .= " AND p.post_type = 'product'";
-		$query['where'] .= " AND p.ID NOT IN ( " . implode( ',', $exclude_ids ) . " )";
-		$query['where'] .= " AND pm.meta_value IN ( 'visible', 'catalog' )";
-
-		if ( get_option( 'woocommerce_hide_out_of_stock_items' ) === 'yes' ) {
-			$query['where'] .= " AND pm2.meta_value = 'instock'";
-		}
-
-		$relate_by_category = apply_filters( 'woocommerce_product_related_posts_relate_by_category', true, $this->get_id() );
-		$relate_by_tag      = apply_filters( 'woocommerce_product_related_posts_relate_by_tag', true, $this->get_id() );
-
-		if ( $relate_by_category || $relate_by_tag ) {
-			$query['where'] .= ' AND (';
-
-			if ( $relate_by_category ) {
-				$query['where'] .= " ( tt.taxonomy = 'product_cat' AND t.term_id IN ( " . implode( ',', $cats_array ) . " ) ) ";
-				if ( $relate_by_tag ) {
-					$query['where'] .= ' OR ';
-				}
-			}
-
-			if ( $relate_by_tag ) {
-				$query['where'] .= " ( tt.taxonomy = 'product_tag' AND t.term_id IN ( " . implode( ',', $tags_array ) . " ) ) ";
-			}
-
-			$query['where'] .= ')';
-		}
-
-		$query['limits'] = " LIMIT {$limit} ";
-		$query           = apply_filters( 'woocommerce_product_related_posts_query', $query, $this->get_id() );
-
-		return $query;
-	}
-
 	/**
 	 * Save taxonomy terms.
 	 *
diff --git a/includes/wc-product-functions.php b/includes/wc-product-functions.php
index 0c89e29bb48..8d4f7cde9dc 100644
--- a/includes/wc-product-functions.php
+++ b/includes/wc-product-functions.php
@@ -700,7 +700,7 @@ function wc_get_product_variation_attributes( $variation_id ) {
  * @return array
  */
 function wc_get_product_cat_ids( $product_id ) {
-	$product_cats = wp_get_post_terms( $product_id, 'product_cat', array( "fields" => "ids" ) );
+	$product_cats = wc_get_product_term_ids( $product_id, 'product_cat' );
 
 	foreach ( $product_cats as $product_cat ) {
 		$product_cats = array_merge( $product_cats, get_ancestors( $product_cat, 'product_cat' ) );
@@ -751,3 +751,116 @@ function wc_get_product_visibility_options() {
 		'hidden'  => __( 'Hidden', 'woocommerce' ),
 	) );
 }
+
+/**
+ * Get related products based on product category and tags.
+ *
+ * @since  2.7.0
+ * @param  int   $product_id  Product ID.
+ * @param  int   $limit       Limit of results.
+ * @param  array $exclude_ids Exclude IDs from the results.
+ * @return array
+ */
+function wc_get_related_products( $product_id, $limit = 5, $exclude_ids = array() ) {
+	global $wpdb;
+
+	$product_id     = absint( $product_id );
+	$exclude_ids    = array_merge( array( 0, $product_id ), $exclude_ids );
+	$transient_name = 'wc_related_' . $product_id;
+	$related_posts  = get_transient( $transient_name );
+	$limit          = $limit > 0 ? $limit : 5;
+
+	// We want to query related posts if they are not cached, or we don't have enough.
+	if ( false === $related_posts || count( $related_posts ) < $limit ) {
+		$cats_array = apply_filters( 'woocommerce_product_related_posts_relate_by_category', true, $product_id ) ? apply_filters( 'woocommerce_get_related_product_cat_terms', wc_get_product_term_ids( $product_id, 'product_cat' ), $product_id ) : array();
+		$tags_array = apply_filters( 'woocommerce_product_related_posts_relate_by_tag', true, $product_id ) ? apply_filters( 'woocommerce_get_related_product_tag_terms', wc_get_product_term_ids( $product_id, 'product_tag' ), $product_id ) : array();
+
+		// Don't bother if none are set, unless woocommerce_product_related_posts_force_display is set to true in which case all products are related.
+		if ( empty( $cats_array ) && empty( $tags_array ) && ! apply_filters( 'woocommerce_product_related_posts_force_display', false, $product_id ) ) {
+			$related_posts = array();
+		} else {
+			// Generate query - but query an extra 10 results to give the appearance of random results when later shuffled.
+			$related_posts = $wpdb->get_col( implode( ' ', apply_filters( 'woocommerce_product_related_posts_query', wc_get_related_products_query( $cats_array, $tags_array, $exclude_ids, $limit + 10 ), $product_id ) ) );
+		}
+
+		set_transient( $transient_name, $related_posts, DAY_IN_SECONDS );
+	}
+
+	shuffle( $related_posts );
+
+	return array_slice( $related_posts, 0, $limit );
+}
+
+/**
+ * Retrieves product term ids for a taxonomy.
+ *
+ * @since  2.7.0
+ * @param  int    $product_id Product ID.
+ * @param  string $taxonomy   Taxonomy slug.
+ * @return array
+ */
+function wc_get_product_term_ids( $product_id, $taxonomy ) {
+	return wp_list_pluck( get_the_terms( $product_id, $taxonomy ), 'term_id' );
+}
+
+/**
+ * Builds the related posts query.
+ *
+ * @since 2.7.0
+ * @param array $cats_array  List of categories IDs.
+ * @param array $tags_array  List of tags IDs.
+ * @param array $exclude_ids Excluded IDs.
+ * @param int   $limit       Limit of results.
+ * @return string
+ */
+function wc_get_related_products_query( $cats_array, $tags_array, $exclude_ids, $limit ) {
+	global $wpdb;
+
+	// Arrays to string.
+	$exclude_ids = implode( ',', array_map( 'absint', $exclude_ids ) );
+	$cats_array  = implode( ',', array_map( 'absint', $cats_array ) );
+	$tags_array  = implode( ',', array_map( 'absint', $tags_array ) );
+
+	$limit           = absint( $limit );
+	$query           = array();
+	$query['fields'] = "SELECT DISTINCT ID FROM {$wpdb->posts} p";
+	$query['join']   = " INNER JOIN {$wpdb->postmeta} pm ON ( pm.post_id = p.ID AND pm.meta_key='_visibility' )";
+	$query['join']  .= " INNER JOIN {$wpdb->term_relationships} tr ON (p.ID = tr.object_id)";
+	$query['join']  .= " INNER JOIN {$wpdb->term_taxonomy} tt ON (tr.term_taxonomy_id = tt.term_taxonomy_id)";
+	$query['join']  .= " INNER JOIN {$wpdb->terms} t ON (t.term_id = tt.term_id)";
+
+	if ( 'yes' === get_option( 'woocommerce_hide_out_of_stock_items' ) ) {
+		$query['join'] .= " INNER JOIN {$wpdb->postmeta} pm2 ON ( pm2.post_id = p.ID AND pm2.meta_key='_stock_status' )";
+	}
+
+	$query['where']  = ' WHERE 1=1';
+	$query['where'] .= " AND p.post_status = 'publish'";
+	$query['where'] .= " AND p.post_type = 'product'";
+	$query['where'] .= " AND p.ID NOT IN ( {$exclude_ids} )";
+	$query['where'] .= " AND pm.meta_value IN ( 'visible', 'catalog' )";
+
+	if ( 'yes' === get_option( 'woocommerce_hide_out_of_stock_items' ) ) {
+		$query['where'] .= " AND pm2.meta_value = 'instock'";
+	}
+
+	if ( $cats_array || $tags_array ) {
+		$query['where'] .= ' AND (';
+
+		if ( $cats_array ) {
+			$query['where'] .= " ( tt.taxonomy = 'product_cat' AND t.term_id IN ( {$cats_array} ) ) ";
+			if ( $relate_by_tag ) {
+				$query['where'] .= ' OR ';
+			}
+		}
+
+		if ( $tags_array ) {
+			$query['where'] .= " ( tt.taxonomy = 'product_tag' AND t.term_id IN ( {$tags_array} ) ) ";
+		}
+
+		$query['where'] .= ')';
+	}
+
+	$query['limits'] = " LIMIT {$limit} ";
+
+	return $query;
+}
diff --git a/templates/single-product/related.php b/templates/single-product/related.php
index 330f6356030..d3570b888e4 100644
--- a/templates/single-product/related.php
+++ b/templates/single-product/related.php
@@ -13,7 +13,7 @@
  * @see 	    https://docs.woocommerce.com/document/template-structure/
  * @author 		WooThemes
  * @package 	WooCommerce/Templates
- * @version     1.6.4
+ * @version     2.7.0
  */
 
 if ( ! defined( 'ABSPATH' ) ) {
@@ -26,7 +26,7 @@ if ( empty( $product ) || ! $product->exists() ) {
 	return;
 }
 
-if ( ! $related = $product->get_related( $posts_per_page ) ) {
+if ( ! $related = wc_get_related_products( $product->get_id(), $posts_per_page, $product->get_upsell_ids() ) ) {
 	return;
 }
 
@@ -37,7 +37,6 @@ $args = apply_filters( 'woocommerce_related_products_args', array(
 	'posts_per_page'       => $posts_per_page,
 	'orderby'              => $orderby,
 	'post__in'             => $related,
-	'post__not_in'         => array( $product->id ),
 ) );
 
 $products                    = new WP_Query( $args );