How to add a page to the Yoast breadcrumbs

Here’s the general principle of what you need to do:

1. Hook into the wpseo_breadcrumb_links or wp_seo_get_bc_ancestors API filters.
2. Add your Blog into the WordPress SEO Breadcrumb $links array, using array_splice.

Place this in your theme’s functions.php:

/**
 * Conditionally Override Yoast SEO Breadcrumb Trail
 * http://plugins.svn.wordpress.org/wordpress-seo/trunk/frontend/class-breadcrumbs.php
 * -----------------------------------------------------------------------------------
 */

add_filter( 'wpseo_breadcrumb_links', 'wpse_100012_override_yoast_breadcrumb_trail' );

function wpse_100012_override_yoast_breadcrumb_trail( $links ) {
    global $post;

    if ( is_home() || is_singular( 'post' ) || is_archive() ) {
        $breadcrumb[] = array(
            'url' => get_permalink( get_option( 'page_for_posts' ) ),
            'text' => 'Blog',
        );

        array_splice( $links, 1, -2, $breadcrumb );
    }

    return $links;
}

Note: You may need to update the code specific to your site or needs, but the general idea stays the same.