What's scarier, the question or the answer?
If you were asked which player would be the hardest to replace in the event of a long-term injury, the answer would be pretty simple: Henrik Lundqvist. But if you expand the scope of that question, the next answer would most likely be Ryan McDonagh (or, as we saw last year, maybe Mats Zuccarello).
Even if McDonagh wouldn't be the top name on your list, you have to admit that any long-term struggles for the captain would be a critical blow to a defense that already looks as though it's been patched together with a glue stick and some scotch tape.