I went down a 1997 Expansion Draft rabbit hole this morning...
Anyways, you could protect 15 players in total... after both teams took turns picking one player combined from each team, you could protect 3 more, and again in the next round. Anybody in the organization with major league service, or who has reached Rule 5 eligibility was eligible to be drafted.
Let's say MLB very abruptly decides there are two expansion teams starting in April and you need to protect 15 eligible players*, who would they be? Which 4 would you protect in the next round (assuming 1 of your top 4 gets taken)? Which 4 would you protect in the next round (again, assuming 1 of your top 4 gets taken)?
*Safe to assume that any prospects who need to be protected were protected from the Rule 5 Draft, so you can likely just focus on the 40-Man Roster unless any of the minor league signings this year really catch your fancy.
I'll go:
Pitchers: Kyle Finnegan, Jack Flaherty, Kenley Jansen, Jackson Jobe, Troy Melton, Casey Mize, Reese Olson, Tarik Skubal, Will Vest
Catchers: Dillon Dingler
Infield: Colt Keith, Spencer Torkelson, Gleyber Torres
Outfield: Kerry Carpenter, Riley Greene, Wenceel Perez
Round 2: Tyler Holton, Kenley Jansen, Parker Meadows, Zach McKinstry
Round 3: Drew Anderson, Brant Hurter, Keider Montero, Matt Vierling
Pretty tricky, but I thought I'd put that out there.