I listen to podcasts, but almost always on my iPhone and almost never on my computer through iTunes. However, any time I open iTunes, it tries to download new podcast episodes. Is there a way to prevent this?

I tried plugging in my iPhone, going to the Podcasts tab, and unchecking Sync Podcasts, but this resulted in a dialog box asking if I'm sure I do not want to sync podcasts, and informing me that if I continue, all existing podcasts on my iPhone will be deleted. That's not my desired result, of course.