Retrieve php array based on it's position

<?php

$userRank = array(
    "Nightowl",
    "Demon Hunter",
    "Shadow Walker",
    "Legend"
);

$userLevel = array(
    "Level 5",
    "Level 10",
    "Level 15",
    "Level 20",
);


$deck = array();

foreach($userRank as $rank){
    foreach($userLevel as $level){
        $deck[] = array("level" => $level, "rank" => $rank);
    }
}

shuffle($deck);
$getVal = array_shift($deck);

echo $getVal['level'] . ' ' . $getVal['rank'];

?>

The end result of this is that the array retrieves random values from the provided a arrays.

Level 10 Nightowl

Level 20 Shadow Walker

What I want is it to output the values according to their index.

Level 5 Nightowl

Level 10 Demon Hunter

Level 15 Shadow Walker

Level 20 Legend

but I want that also to be random in the result of $getVal['level] and $getVal['rank']

So if I call that function, it will call a random line of the 4 I provided but they will match based on their index