Here's the thing: San Diego Padres closer Mason Miller would improve and be a fit for 29 teams. If he's available for the right price — which figures to be a commanding one, as the star reliever is under contract through 2029 — at the MLB trade deadline, it's more about who needs the premier reliever more and who can justify giving up a haul to do so with respect to how close they are to World Series contention. Those teams are out there, though.
Granted, just one of them will end up with Miller. And with that, here are the three best trade fits for Miller. The Cubs are in the thick of things – Chicago has possession of the No.
1 National League wild-card seed at 61-46 – but they have holes on their pitching staff, and acquiring Miller would emphatically fill one of those voids. Chicago's bullpen is tied for 22nd in opponent batting average (.247), tied for 14th in WHIP (1.31) and 14th outright in ERA (3.97). Moreover, they've collectively blown 17 saves, Jacob Webb leads their staff with just five saves and the Cubs have had 12 different pitchers record a save.
Plug Miller in the closer role for the Cubs, and the likes of Webb, Daniel Palencia and Trent Thornton, who are all having successful 2026 campaigns, serve as the bridge to the ninth inning. Miller has been sensational for the Padres this season. The right-handed reliever is 27 for 27 in save situations, while owning an 0.81 ERA, an 0.81 WHIP, a 515 ERA+ and totaling 83 strikeouts and 2.6 wins above replacement over 44 ⅔ innings pitched.
What could halt a Miller pursuit by the Cubs, though, is them potentially feeling it's more prudent and needed to acquire a top-of-the-rotation arm before trading a considerable package for a reliever; Chicago's starting rotation has been a roller-coaster this season. The White Sox are five wins away from matching their 2025 win total (60), as they stand atop the American League Central at 55-51. Do they make a move to fortify the late innings with the aim of complementing an emerging starting rotation (Davis Martin and Sean Burke continue to progress, with Anthony Kay emerging this season)?
Now, Chicago's bullpen has held its own, as it's currently eighth in MLB in opponent batting average (.231), 11th in ERA (3.94) and tied for 17th in WHIP (1.32). At the same time, the White Sox have been operating on a by-committee approach in the ninth inning. Moreover, they've blown 20 saves, which is tied for third-most in the sport.
Acquiring Miller would give the White Sox their undisputed closer, taking the burden off younger/less experienced relievers like Bryan Hudson and Grant Taylor to shut the door. Plus, veteran Seranthony Domínguez, who owns a 4.21 ERA and is 12 of 17 in save situations for Chicago, previously found more success in a setup role with the Philadelphia Phillies, Baltimore Orioles and Toronto Blue Jays. Miller, who leans on his slider and four-seamer, ranks in the 100th percentile of MLB in whiff rate (47.8%) and average fastball velocity (101.4 mph), the 98th percentile in opponent average exit velocity (84.9 mph) and the 97th percentile in chase rate (37.6%), according to Statcast.
He has also recorded four-plus outs in six appearances. All that said, one could argue the White Sox should firmly establish themselves as a contender, rather than just an emerging force, before making a trade of this magnitude for their bullpen. For the first time in a decade, the Pittsburgh Pirates — who are one game out of the third NL wild-card seed at 55-53 — are definitively moving in the right direction and have merit to make a move to tie up a loose end.
That move could be trading for Miller. For starters, the Pirates have struggled when they go to the bullpen. To date, their relief unit is 24th in ERA (4.41), tied for 23rd in WHIP (1.40) and 17th outright in opponent batting average (.241).
Left-hander Gregory Soto has held his own as the team's primary closer, but he has also blown five saves, and Pittsburgh has collectively blown 19 saves, which is tied for sixth-most in the sport. Where the logic in the Pirates trading for Miller differs from the White Sox — who are in a similar situation with being in playoff contention after a prolonged stretch of not being in that mix — is that Pittsburgh plays in a deeper and more challenging division; the NL Central has three teams with a winning record this season, whereas the AL Central has underwhelmed and sent just one team to the AL Championship Series since 2017. Elsewhere, second baseman Brandon Lowe and first baseman/right fielder Ryan O'Hearn have been impactful veteran complements, while rookie Konnor Griffin (prior to going on the injured list with a finger injury) and fellow former top-10 pick Nick Gonzales have made strides, while outfielder Bryan Reynolds is having a bounce-back season en route to Pittsburgh being second in runs scored (563) and first in hits (980).
Sure, the Pirates' starting rotation has slumped some, but Paul Skenes is the defending NL Cy Young Award winner, Mitch Keller is a proven commodity and Braxton Ashcraft, Bubba Chandler and Jared Jones are still getting their feet beneath them; this is a starting staff with high-end upside. Pittsburgh could base a trade package for Miller around outfielder Jhostynxon Garcia, 2025 first-rounder Seth Hernandez and right-hander Carmen Mlodzinski, among other assets. You have to give to get.
One could argue it's not worth trading a trio of top-10 prospects or a similar trade package in value for a pitcher, regardless of how elite they may be, who only pitches a fraction of the innings of a starting pitcher, especially when compared to an All-Star-caliber one, based sheerly on usage. That being said, if you're going to make such a move for a closer, Miller is on the shortlist of relievers you would do it for — and he could be what pushes the Pirates into the playoffs for the first time since 2015.
