PHP Crawler动态加载内容

I am trying to crawl the leaderboard table from this url, but it is loaded dynamically after a few milliseconds, so I can't access it from the dom. I am using this code so far:

$dom = new DomDocument();
$dom->loadHTMLFile("http://www.pokerstars.eu/poker/tournaments/micro-millions/player-of-the-series/");
$el = $dom->getElementById('siteHeader');

Where siteHeader is loaded in the dom, however, the div I want to access is not there straight away. Its added after a second or so.

Is there any way to put in some kind of sleep, so I have this code in my DOM?