Custom Variable in Postbit

[evenmonkeys]

Plugin: postbit_display_start

$gameuserid = $post['userid'];
$player_sql = $vbulletin->db->query("SELECT * FROM gametable WHERE userid = '$gameuserid'");
$player = $vbulletin->db->fetch_array($player_sql);
  $player_score = $player['score'];

Template: postbit_legacy

Score: $player_score

Gives this error:
Fatal error: Call to a member function query() on a non-object in /forums/includes/class_postbit.php(265) : eval()'d code on line 86