我看不出仅使用标准参数就可以做到这一点，但您可以使用过滤器：

function link_hack_wpse_($output,$args) {
  global $page, $numpages;
  $xofy = $page.\' of \'.$numpages;
  if (1 == $page) {
    $output = str_replace($args[\'after\']," $xofy{$args[\'after\']}",$output);
  } elseif ($page == $numpages) {
    $output = str_replace($args[\'before\'],"{$args[\'before\']}$xofy ",$output);
  } else {
    $output = str_replace(\'</a><a\',"</a> $xofy <a",$output);
  }
  return $output;
}
add_filter(\'wp_link_pages\',\'link_hack_wpse_\',10,2);

$args = array(
  \'before\'           => \'<p>\',
  \'after\'            => \'</p>\',
  \'next_or_number\'   => \'next\',
  \'separator\'        => \'\',
  \'nextpagelink\'     => __( \'Next\' ),
  \'previouspagelink\' => __( \'Previous\' ),
  \'pagelink\'         => \'%\',
  \'echo\'             => 1
);defaults

wp_link_pages( $args );