In both the 1992 (Rockies/Marlins) and 1997 (D'Backs/Rays) expansion drafts, the new MLB teams were able to select players off the existing teams' 40 man roster. Each existing team was able to protect 15 players on their 40 man. The draft is three rounds, and each existing team loses a player in each of the first two rounds and, potentially, in the third as well (it is only half as long). After each of the first two rounds, existing teams can protect an additional three players.

Let's imagine that MLB expands again after the 2012 season. You're Sandy Alderson. Which players on the Mets 40 man roster do you protect?

Let's add a few notes here, first.

1) Players on the 60 day DL have to be protected or exposed to the draft, so Mike Pelfrey and Pedro Beato should be considered part of the 40 man.

2) The players' contracts, service time, etc. don't change if selected. This should be obvious.

3) Any options for 2013 have to be exercised before protections. (I'm mostly adding this to remove any ambiguity around David Wright's voidable one.) Options for 2014 and beyond can wait.

My Protections

These are in no particular order:

1. Ike Davis
2. Daniel Murphy
3. Ruben Tejada
4. David Wright
5. Kirk Neiuwenhuis
6. Lucas Duda
7. Jonathon Niese
8. R.A. Dickey
9. Josh Thole
10. Jeurys Familia
11. Jenrry Mejia
12. Wilmer Flores
13. Jordany Valdespin
14. Dillon Gee
15. Caeser Puello

That leaves a bunch of notables exposed: Juan Legares, Bobby Parnell, Reese Havens, Johan Santana, Jason Bay, Andres Torres, and the entire bullpen; Pelfrey too, for what it's worth. Note that Harvey, Wheeler, and Nimmo aren't at risk because they're not on the 40 man roster.
The hardest choices were including Flores, Gee, and Puello, especially over Lagares, Parnell, and Havens. In fact, I originally had Gee on the unprotected list, but given that Pelfrey's gone one way or another, I probably don't want to hurt our rotation and SP depth. Lagares over Flores and Puello is simply me not knowing the minors well enough -- I'm sure someone with more knowledge of our system could do better here.
I figure that Lagares or Parnell are most likely to be selected in the first round, and I'd pull back the other, Havens, and probably Santana.
I pull back Santana because I think there's actually a pretty high chance he's taken in the second round over the rest of the guys I'd have exposed otherwise. It's slim pickings with Justin Turner, Manny Acosta, Robert Carson, Torres, Jeremy Hefner, Zach Lutz, and a few others leading the way, and while I could justify protecting any of them, I don't think they're worth it, even if you include the salary relief from Santana being plucked.
After the second round, if Torres hasn't been taken, I pull back him and two others -- maybe Acosta, maybe Hefner, I really don't know.
Note that Bay isn't protected. Bay is easy to justify leaving exposed, as his huge salary and questionable value makes it unlikely to being selected.
Where'd I err? Who would you protect?