It's a very solid team. What I would do - try to trade Vidro for a top closer. It won't happen, but you've got to try. Wait a couple of weeks into the season and then try again - to whichever guy has Mark Loretta or some other trash filling his 2b spot.
I'd put any of your bench in over Dunn.
Finally, here's a list of your starters that haven't missed significant time in the last 2 years:
That could be a problem, unless you're lucky. Maybe you should try to trade Vidro for a starter, instead. Although you don't have a top notch closer, you do have 5 closers. At least 4 should keep their jobs. Your era/whip won't be great, but you'll be fine in saves.