When the A's opted against using Mason Miller in a save opportunity on Wednesday night, it felt as if it was a matter of when, not if, he was going to get traded. Sure enough, he was just sent to the San Diego Padres alongside starting pitcher J.P. Sears, according to ESPN's Jeff Passan.
BREAKING: The San Diego Padres are acquiring closer Mason Miller and starter J.P. Sears from the A's, sources tell ESPN.
— Jeff Passan (@JeffPassan) July 31, 2025
The full extent of the return is unknown as of this writing, but the Padres are giving up their top prospect (and the No. 3 overall prospect in the sport, per MLB Pipeline), Leo De Vries, in the deal. It's a lot to give up, but it's hard to blame A.J. Preller for going all-in.
Even without Miller, the Padres had arguably the best bullpen in the sport. Now with him, that unit is borderline unfair.
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MLB trade grades: Padres pay premium price for Mason Miller
There's no sugarcoating how lofty a price Preller paid to land Miller. De Vries is one of the game's best prospects with a legitimate superstar ceiling. With that being said, this is Mason Miller we're talking about here, and the Padres have him under cheap club control through the 2029 campaign.
Miller burst onto the scene last season and has been one of MLB's best closers since. He averages over 101 mph with his fastball, and pairs that with a slider that generates a 50.8 percent whiff rate and has held the opposition to a .111 average. With those factors in mind, it comes as no surprise that Miller has a 39.1 percent strikeout rate, good for the 100th percentile according to Baseball Savant.
The Padres had three All-Star relievers without Miller. Adding him to those three All-Stars - Robert Suarez, Jason Adam, and Adrian Morejon - along with Jeremiah Estrada, is just ridiculous. Chances are, the Padres will consider trading Suarez, as he can hit free agency after the year, to fill another hole, but even without him, this bullpen is the best in the sport by far.
Adding JP Sears on top of Miller is solid business as well. He won't wow anyone, but he's been a decent enough back-end arm for a couple of years now, and he's under control for three more years.
Yes, this Padres team has some questions, but if they lead any given game after five or six innings, chances are, it's game over thanks to their absurd bullpen. That's ridiculous, and cannot be overlooked even with the steep price they paid for Miller.
Padres trade grade: B+
While I think the Padres did well to land the most valuable closer in the game, the A's are the clear winners of this trade. Sure, parting with Miller hurts, but even with him, they're one of the worst teams in the sport. Now, the A's have acquired a future superstar in De Vries who can help lead them long-term.
De Vries is a switch-hitting shortstop who projects to be a true five-tool superstar. He's the kind of player you build a franchise around. The A's got him for a reliever. That's a no-brainer.
Sure, a .767 OPS in High-A might not stick out, but it's important to note that De Vries is 18 years old. An 18-year-old even being in High-A, let alone hitting at an above-average level, is pretty unheard of. There's a chance he'll be in the majors by age 20, giving the A's a chance to roster a young superstar for a very long time if John Fisher is ever willing to open the purse strings.
In addition to De Vries, the A's are acquiring three pitching prospects per Passan. The most intriguing of the bunch is Braden Nett, San Diego's top pitching prospect, who has a 3.39 ERA and struck out over 10 batters per nine innings across 17 starts at the Double-A level this season. He could easily be MLB-ready by sometime next season.
Henry Baez and Eduarniel Nunez aren't quite as exciting, but they're both in the midst of outstanding years. Baez has a sub-2.00 ERA in 20 starts at the Double-A level, and Nunez is a reliever who has already made four big league appearances.
The Padres got a bonafide superstar closer with tons of club control, which, again, cannot be overlooked, but the price they paid is absurd. The A's got arguably the best prospect in the sport, and three very real pitching prospects all for essentially a closer. Miller is a very good one, of course, but relievers only have so much value. This is a good deal for San Diego, and an absolute slam dunk for the A's.