They probably just move the ones with the biggest projections - Olson, Manaea, Chapman, and Bassitt. Maybe even just 3 of them.
If I had to guess one who stays, I would say Bassitt, since he probably has the least trade value as the oldest and only one year of control left. That he projects to make the least of the 4 probably helps, too.
One never discussed name on the list that might interest Boston is Chad Pinder. Good overall player, but he does not really excel either offensively or defensively (at least at 2B). But he might be available, doesn't make a lot of cash, and plays a slew of positions, which is something Bloom clearly values...