Travel Yufuin to Fukuoka to board ferry to South Korea

Hi there,

I'm looking at purchasing the 14 day JR pass to travel south from Tokyo loosely following the suggested itinerary on the website. I need to finish my trip in Fukuoka, however, in order to board a ferry for South Korea.
Can you advise if the JR pass would cover my travel from Yufuin to Fukuoka, and how much it would cost if not. Could you also recommend any alternative routes that take me in the same direction but possibly from different stations.

Many thanks,

Jossie