create shortcode that changes url endpoint

it’s hard for me to say if the remote API allows you to get stats for given player only, but… There’s another way and I would go for it just to minimize the number of requests to remote API…

class Remote_Player_API {
    private static $instance;

    private $remote_data;

    public static function init() {
        if ( ! self::$instance ) {
            self::$instance = new Remote_Player_API();
        }
    }

    protected function __construct() {
        $this->register_shortcodes();
    }

    protected function get_remote_api_data() {
        // you can also use transients here and cache remote responses for some time to optimize API calls even more
        if ( ! $this->remote_data ) {  // obtain remote data only, if we haven't done it already, so the request will be done only once
            $response = wp_remote_get('http://api-address-hidden-for-security/statsajax.php?action=rankedplayerslist&eventid=5');
            $this->remote_data = json_decode( utf8_encode( $response['body'] ), TRUE );
        }
        return $this->remote_data;
    }

    protected function register_shortcodes() {
        add_shortcode( 'individualPlayer', array( $this, 'shortcode_callback_individualPlayer' ) );
    }

    public function shortcode_callback_individualPlayer( $atts ) {
        $atts = shortcode_atts( array(
            'player_number' => 0,  // you have to pass player_number as attribute
        ), $atts );
        ob_start();
        ?>
        <div class="s-players">
            <div class="container">
                <?php
                    foreach ( $this->get_remote_api_data() as $player ) :
                        if ( $player['Numero'] != $atts['player_number'] ) continue;
                ?>
                <p><?php echo esc_html( $player['Evento'] ); ?></p>
                <p><?php echo (int)$player['Numero']; ?></p>
                <p><?php echo esc_html( $player['Jugador'] ); ?></p>
                <?php endforeach; ?>
            </div>
        </div>
        <?php
        return ob_get_clean();
    }
}
Remote_Player_API::init();

Disclaimer: I’ve written this code in here, so there might be some typos 😉