Let me preface this story by saying that yes, I do understand why the Seattle Mariners trading for Mason Miller might not make sense. For one, the Mariners already have an elite closer in Andrés Muñoz, who was an All-Star this year and holds an ERA of 1.35 and a WHIP well under 1.00.
Plus, any team acquiring Miller would likely have to give up multiple top-level prospects, and the Mariners likely wouldn't want to do that for a position that may be redundant when they could add a different bullpen arm for much less.
And still — if the Mariners really want to be as aggressive as President of Baseball Operations Jerry Dipoto says they do, then why not? Miller could become an elite 8th inning setup role and still act as the fill-in closer if Muñoz is down for a day. Instead of redundency, think of it as doubling down and forming the best two-inning relief pitcher combination in baseball. Going from Miller in the eighth to Muñoz in the ninth would be nightmare fuel for opposing offenses, especially if they had to face Matt Brash in the seventh.
Jerry Dipoto says Mariners will be aggressive for bullpen arms
After adding first baseman Josh Naylor, the Mariners are off to a fabulous start at the trade deadline, but Dipoto isn't satisfied, telling MLB Network Radio on Sirius XM that the team will be as aggressive "as anybody" in the next few days to get bullpen help.
The aforementioned Muñoz and Brash are both reliable, high-leverage arms. Gabe Speier isn't often used super late in games, but he can be counted on, too. Outside of that group, Seattle gets a little thin and that's why Dipoto wants to beef up the bullpen.
This is a season of "why not" for the Mariners. Why not add Naylor? Why not go super big at the trade deadline? Why not sacrifice some prospects to get an elite arm that immediately increases the team's odds at a deep playoff run?