I have the following nginx vhost config:

server {
    listen 80 default_server;

    access_log /path/to/site/dir/logs/access.log;
    error_log /path/to/site/dir/logs/error.log;

    root /path/to/site/dir/webroot;
    index index.php index.html;

    try_files $uri /index.php;

    location ~ \.php$ {
            if (!-f $request_filename) {
                    return 404;
            }

            fastcgi_pass localhost:9000;
            fastcgi_param SCRIPT_FILENAME /path/to/site/dir/webroot$fastcgi_script_name;
            include /path/to/nginx/conf/fastcgi_params;
    }
}

I want to redirect all requests that don't match files which exist to index.php. This works fine for most URIs at the moment, for example:

example.com/asd
example.com/asd/123/1.txt

Neither of asd or asd/123/1.txt exist so they get redirected to index.php and that works fine. However, if I put in the url example.com/asd.php, it tries to look for asd.php and when it can't find it, it returns 404 instead of sending the request to index.php.

Is there a way to get asd.php to be also sent to index.php if asd.php doesn't exist?