Video on the main page

Hey guys!
I have a client, who has a video on his main page and its hurts page speed a lot. This is a WP website and they use some plugin (Smart Slider 3) for inserting this video from YouTube.
I can`t delete the video (site owners insist to keep it) but it seems like it harms SEO.
Can anyone suggest the least painful (for SEO) method of inserting YouTube video to the main page?

There is no such a think, just add the video and test it out.