Granted, that is an unspoken worry for the Mariners, everyone just assumes he's going to be lights-out, but my two worries are these: 1. It's much easier to be the closer on a team with zero expectations, just throw free and easy, and let the chips fall where they may (what's that? three cliches in one sentence?). 2. There have been way too many one year wonders when it comes to closers -- that's the scary part. If Aardsma falters, probably Mark Lowe will be given a chance, he was very good at times last year, and he did have three saves. The Mariners seem to be hopelessly in love with Brandon League, so maybe he's Plan B. This whole question is the reason I did not like the Morrow trade, which I think will come back to bite the Mariners in the rear end when it's all said and done.
Edit: PS -- Article "whistling-past-the-graveyard" on Aardsma