The first five you name have a chance to bring back a prospect, even if the ceiling is "ML utility player for a few seasons". If you include Duensing, he remains the cliched sweetener to some other deal, and then I suggest most of the other guys in the bullpen with significant service time, namely Guerrier, Burton, and Swarzak, should be on the table as well. A team that likes FIP may give Swarzak a look, while one that likes ERA would lean toward Duensing. A team needing a short term solution might like Guerrier's numbers. The Dodgers might give us another Sulbaran for Burton. Fien does belong in your first list because his numbers across the board look strong and he might fetch an actual prospect - he's the one guy a team might acquire both because they need him and they don't want a rival to get him cheaply. I don't mean to hold a fire sale and dispose of all the bullpen. We have young guys ready but not an infinite supply. (Until the recent draft of hordes of relief arms starts to come through the pipeline. )