Padres Acquire Mason Miller, JP Sears

The Padres are once again grabbing deadline headlines, as they’ve swung a trade that’ll bring star closer Mason Miller and lefty JP Sears to San Diego while sending a four-player package led by top shortstop prospect Leo De Vries back to the Athletics. The A’s will also add right-handers Braden Nett, Henry Baez and Eduarniel Nunez in the blockbuster deal.  The deal is now official.

It’ll go down as one of the more stunning trades of the 2025 deadline. Miller is one of the sport’s most highly regarded relievers — an All-Star and fourth-place finisher in American League Rookie of the Year voting just last season. He’s controlled for another four years beyond the current season. De Vries, meanwhile, currently sits as the No. 5 prospect in the entire sport on Baseball America’s latest rankings.

It also sets the stage for a fair bit of other dealing from the Padres, who’ve been discussing current closer Robert Suarez and righty Dylan Cease in trade talks. Either or both could change hands now in trades that simultaneously net younger talent and free up payroll space for San Diego to pursue upgrades in left field, behind the plate and/or on the bench. Both Miller and Sears are still in their pre-arbitration years and thus earning just over the league minimum. USA Today’s Bob Nightengale suggests that there are no current plans to trade Suarez, though with president of baseball operations A.J. Preller at the helm for the Padres, nothing should ever be expressly ruled out. ESPN’s Buster Olney reports that both Suarez and Cease are still being discussed.

The addition of Miller strengthens what was already a powerhouse San Diego bullpen (though, as mentioned, could set the stage for a Suarez trade as well). San Diego relievers have pitched to an MLB-best 2.97 earned run average on the season and rank fifth with a collective 24.1% strikeout rate.

Miller, despite carrying a fairly pedestrian 3.76 ERA, will provide a massive upgrade. The majority of his trouble this year came in a rough month from early May to early June. He’s rattled off 14 innings of one-run ball with 18 strikeouts and four walks since June 15 and, of course, was one of the most dominant bullpen arms in the game a year ago. Miller has pitched 136 2/3 big league innings and carries a 3.16 ERA with a superlative 37.3% strikeout rate and 10.2% walk rate. He’s saved 48 games and tallied one hold in his career to date and has blown only six opportunities.

Certainly, the tools are there for Miller’s bottom-line results to align with the very best arms in the sport. No one in baseball throws harder than his average 101.1 mph four-seamer, and Miller’s 20.4% swinging-strike rate trails only Josh Hader and Fernando Cruz for the top mark among pitchers with even 10 innings pitched this season. Dating back to 2024, he’s fanned nearly 41% of his opponents and kept his walk rate under 10%. Even in an era where power arsenals with premium bat-missing ability seem to proliferate the sport, the 6’5″ Miller stands above the rest in a tier nearly unto himself.

It’s worth at least considering the possibility that Miller could return to the rotation at some point down the road. Ken Rosenthal and Dennis Lin of The Athletic suggested last night that it was an idea the Padres had considered. Miller was drafted as a starter and made his big league debut in the Athletics’ rotation. Given the Friars’ lack of rotation depth and plethora of talented relievers, they could at least explore the idea of returning Miller to a starting role beginning next season, though there’s obviously some risk in removing him from a role in which he’s found such success.

Regardless of which role Miller holds in the long run, it seems likely he’ll work in relief for the balance of the current season. He’s not yet arbitration-eligible — though he will be this winter — and is controlled for four additional seasons, so it’s only natural that the asking price on the right-hander was exorbitant. The Padres have repeatedly rebuffed teams who’ve come calling for De Vries or top catching prospect Ethan Salas, but San Diego ultimately relented in order to acquire four-plus seasons of arguably the game’s most dominant reliever and Sears — a respectable back-of-the-rotation arm who can help solidify the staff for three-plus years in his own right.

Sears, 29, came to the A’s alongside Ken Waldichuk and Luis Medina in the trade sending Frankie Montas and Lou Trivino to the Yankees. He’s the only one of the pitchers (on either side of the deal) that has held up without a major injury.

While Sears is a pure back-end starter, he’s been a durable source of competitive innings for the A’s. The 5’11” southpaw started 32 games in both 2023 and 2024, and he’s taken the mound 22 times in 2025. This year’s 4.95 ERA is a career-high, though like teammate Luis Severino, more of those struggles have come at home in what’s proving to be a hitter-friendly setting at West Sacramento’s Sutter Health Park. Sears has a 5.48 ERA and has allowed 14 homers in 47 2/3 innings at home, compared to a 4.55 mark and nine round-trippers in 63 1/3 innings on the road.

Over Sears’ past 464 innings with the A’s, the lefty has worked to a combined 4.58 ERA. He’s fanned 20.1% of his opponents in that time and kept his walk rate to a strong 6.7%. Sears sits 92.2 mph on his four-seamer and couples that pitch with a slider that sits 79.5 mph and a changeup that’s averaging 83.4 mph this year. He’s averaging just over five innings per start.

Sears now slots into a rotation group that includes Cease (for now), Nick Pivetta, Yu Darvish, Ryan Bergert and Randy Vasquez. Top starter Michael King has been out for more than two months but is expected to return before season’s end. Both Cease and King are free agents at season’s end.

San Diego has been hopeful of re-signing King, though that’s no guarantee. Next year, they’ll get Joe Musgrove back from Tommy John surgery. A 2026 rotation could well include Musgrove, Pivetta, Darvish, Sears and one of Bergert/Vasquez/Stephen Kolek, though the return of King or acquisition of other rotation arms obviously can’t be ruled out. Regardless, Sears adds some nice depth and will remain affordable. He also still has a pair of minor league option years remaining, giving the Friars plenty of flexibility with the composition of that staff.

The A’s have been reluctant to move Miller, but San Diego’s willingness to include De Vries surely pushed things over the edge. He’s the best prospect moved at a trade deadline since the Padres gutted their farm system to acquire Juan Soto three years ago. Today’s front offices are generally loath to part with prospects who’ve reached this level of acclaim, but the Preller-led Padres are the most aggressive in baseball when it comes to the trade market.

Still just 18 years old, De Vries is a switch-hitting shortstop with power who’s having success in High-A despite his youth. More advanced and experienced opponents haven’t fazed him. He’s hitting .245/.357/.410 (116 wRC+) with eight homers and eight steals despite being one of the youngest players in the league. He draws above-average grades across the board in most scouting reports, with his raw power, in particular, generating plus marks.

De Vries is listed at 6’2″ and 183 pounds, although given his age, he could still grow into more bulk and tap more into his raw power. Baseball America describes him as a potential “centerpiece of a big league club,” touting an all-fields approach from the left side of the plate and a pull-heavy approach from the right side that lets him get to that power more frequently. FanGraphs’ Eric Longenhagen is a bit more bearish, albeit only relative to his elite ranking at BA and at MLB.com (where he’s ranked third in the game). Citing questions about his defensive aptitude and some swing-and-miss, FanGraphs’ report calls De Vries “only” a top-40 or so prospect in the game and has him as more of a strong regular than a superstar.

As with any prospect, there’s a fairly broad range of outcomes, but De Vries’ ceiling is higher than most and he’s on track to reach the majors at an uncommonly young age, giving the A’s more control over his peak physical seasons. A call to the majors in 2027 seems quite feasible, and in a best-case scenario he could even debut late next year. If De Vries incurs injuries or takes a bit longer to adjust to upper-level pitching, that debut could push back to 2028, but even then he’d be in just his age-21 season. Regardless, when the range of likely outcomes is generally agreed upon as something between “above-average everyday shortstop” to “superstar centerpiece of a team,” we’re talking about one of the game’s premier young talents.

De Vries is the clear headliner of the deal, but the three arms headed back to the A’s are hardly mere throw-ins. Nett and Baez were reportedly among the more sought-after prospects in the second tier of a thin Padres farm system. Both are posting strong numbers in Double-A this season.

Nett, 23, has started 17 games and pitched 74 1/3 innings. He’s logged a 3.39 ERA, 26.3% strikeout rate, 10.4% walk rate and 42.3% ground-ball rate. Nett signed with the Padres as an undrafted free agent in 2022 and has pitched his way into genuine prospect status.

Baseball America ranked Nett seventh among San Diego prospects earlier this month. He sits third in their system at MLB.com and 12th at FanGraphs. He sits 95-97 mph with a fastball that can climb to 99 mph. Nett’s slider gets above-average grades from scouts and works with a cutter, changeup and curveball that could all use some additional refinement. He’ll be Rule 5 eligible this offseason and will surely be selected to the A’s 40-man roster by November — if he’s not called upon for a major league look in the season’s final two months.

Baez, meanwhile, ranked 16th in the system at BA, 13th at MLB.com and 27th at FanGraphs. He’s posted a 1.96 ERA in 20 Double-A starts this season but has averaged under five innings per outing. Baez sits in the low to mid-90s with his fastball and tops out around 97. He has better command than Nett but lesser velocity and misses fewer bats. He also features a curveball in the upper 70s and a mid-80s changeup. Baez was already on San Diego’s 40-man roster and will thus go right onto the Athletics’ 40-man roster as well.

The 26-year-old Nunez has already made his major league debut, tossing 4 2/3 innings out of the Padres’ bullpen this year. He’s a pure bullpen prospect who can step right into manager Mark Kotsay’s relief corps, if the A’s choose. He’s sat 97.9 mph with his four-seamer in his brief big league look, and Nunez has sat even higher (98.8 mph) in Triple-A. He couples that pitch with an upper-80s slider and a seldom-used curveball in the low to mid-80s.

San Diego signed Nunez as a minor league free agent over the winter, and he’s made huge gains with what had been previously poor command in the Cubs’ system. Nunez walked 22% of his opponents with Chicago’s Triple-A club a year ago. His 14% mark in Triple-A this season is still problematic but nowhere near as alarming. He also boasts a massive 38.6% chase rate in the minors and an outrageous 21.5% swinging-strike rate.

If Nunez can even come close to replicating those rates in the majors, he’d have the potential to be a high-end relief arm himself. That said, it’s worth bearing in mind that Nunez is already older than the elite reliever for whom he was just traded (Miller), and this is first time he’s really shown any semblance of command in the upper minors. There’s upside here, but Nunez is still very much a work in progress.

There’s rarely a dull deadline when it comes to Preller, and this morning’s early and still fairly stunning swap of one of MLB’s most coveted prospects for one of its best big league relievers leaves plenty of time for further dealing. The Padres have been connected to left fielders like Cleveland’s Steven Kwan and Boston’s Jarren Duran while simultaneously exploring deals involving Cease, Suarez and other members of the current big league roster. More fireworks are surely on the way, but Preller and his Oakland West Sacramento counterpart, David Forst, have kicked things off with a bang.

ESPN’s Jeff Passan first reported the trade of Miller and Sears to the Padres and was also first with the full details on the Athletics’ return. This post was originally published at 10:25am.