I tried using the iframe embed code and the HTML5 player appeared, however, for some reason the iframe was completely breaking my site.
I messed around with the old object embed code and it works perfectly fine. So if you're having problems with the iframe here's the code i used:
<object width="640" height="360">
<param name="movie" value="http://www.youtube.com/embed/VIDEO_ID?html5=1&rel=0&hl=en_US&version=3"/>
<param name="allowFullScreen" value="true"/>
<param name="allowscriptaccess" value="always"/>
<embed width="640" height="360" src="http://www.youtube.com/embed/VIDEO_ID?html5=1&rel=0&hl=en_US&version=3" class="youtube-player" type="text/html" allowscriptaccess="always" allowfullscreen="true"/>
</object>
hope this is useful for someone