This is more of a random musing than anything, but relief pitchers in MLB are such a fickle, interesting breed. You might go from one of the best relievers on your team, to DFA fodder within the course of a year.
And then in some cases, wind up being one of the best arms in a different pen later.
There’s a few that are consistent and reliable year after year, but they’re rare. Many others follow the pattern of being valuable at various times and throwaways at other times.
You almost need to think much differently than other roles on the team as to how to value the relief pitcher if you’re a GM. (And definitely not like A.J. Preller).