Mam blad w grze i probowalem go usunac, lecz nie udalo mi sie, dlatego zwracam sie do was, moze wy mi pomozecie

Mam gre no i jak chce walczyc w Boxing Clubie, to wybieram zawodnika (z ktorym chce walczyc), potem akceptuje i wyskakuje mi taki błąd:
Catchable fatal error: Object of class stdClass could not be converted to string in G:\xampp\htdocs\arm.php on line 114
A o to linijki arm.php (od 101linijki do 117linijki)
Kod
if (strip_tags($_POST['play_id']) && strip_tags($_POST['Submit'])){
$play_id=strip_tags($_POST['play_id']);
$match_info=mysql_query("SELECT * FROM matches WHERE id='$play_id'");
$num = mysql_num_rows($match_info);
$match_fetch=mysql_fetch_object($match_info);
if ($num == "0"){
echo "No such match.";
}elseif ($num != "0"){
if ($match_fetch->bet > $fetch->money){
echo "You do not have enough money to play this game.";
}elseif($match_fetch->bet <= $fetch->money){
if (strtolower($match_fetch->username) == strtolower($username)){
echo "You cannot play yourself sado.";
}elseif (strtolower($match_fetch) != strtolower($username)){
$oppon = mysql_fetch_object(mysql_query("SELECT * FROM user_info WHERE username='$match_fetch->username'"));
$oppon_user = mysql_fetch_object(mysql_query("SELECT * FROM users WHERE username='$match_fetch->username'"));
$wl=explode(":",$oppon->wl);
$play_id=strip_tags($_POST['play_id']);
$match_info=mysql_query("SELECT * FROM matches WHERE id='$play_id'");
$num = mysql_num_rows($match_info);
$match_fetch=mysql_fetch_object($match_info);
if ($num == "0"){
echo "No such match.";
}elseif ($num != "0"){
if ($match_fetch->bet > $fetch->money){
echo "You do not have enough money to play this game.";
}elseif($match_fetch->bet <= $fetch->money){
if (strtolower($match_fetch->username) == strtolower($username)){
echo "You cannot play yourself sado.";
}elseif (strtolower($match_fetch) != strtolower($username)){
$oppon = mysql_fetch_object(mysql_query("SELECT * FROM user_info WHERE username='$match_fetch->username'"));
$oppon_user = mysql_fetch_object(mysql_query("SELECT * FROM users WHERE username='$match_fetch->username'"));
$wl=explode(":",$oppon->wl);
Bardzo prosze o pomoc...