wpengine-noindex-author.php

/**
 * Sets noindex for the wpengine author archive pages.
 *
 * @access public
 * @return void
 */
function noindex_wpengine_author() {
	if (is_author( 'wpengine' )) {

		echo '<meta name="robots" content="noindex">';
	}
}

add_action('wp_head', 'noindex_wpengine_author');