Can you call this a must win? Especially with Calgary showing signs of sputtering out. Perhaps not a must win, but you at least want to secure a playoff birth. Unfortunately this assures us of a series with LA if we make the playoffs (there's no catching Anaheim). I guess you want to avoid a situation where you are going into the playoffs without any momentum. Now, if you draw LA. Do you really wish for home ice advantage? The Canucks have been god awful at home as of late.
Dallas will be fired up for this. They got their ass handed to by Edmonton last night, barely exerted much of an effort so the back end of the back-to-back shouldn't be a big deal for them.
In either case, another poor start would really set red flags. If this continues, you really have to determine whether or not this is a coaching issue or more so on the players and address it in the off-season.