Linking External Hard Drives

I have linked an external hard drive to my helios x3000 media player and wondered if anyone knew whether I could somehow link a second HD when I eventually need extra storage or whether I would just have to swap cables depending on which drive I need to use. If there is a way would the player be able to differentiate between the two drives when I am choosing something to watch?

I have searched around the internet but had no joy.

Thanks to anyone that can help

Phil