Flamethrowing relievers could define this Trade Deadline

Eugenio Suárez may have 36 home runs, but with all due respect to the D-backs’ slugging third baseman, the most impressive power available at this year’s Trade Deadline isn't in the batter's box. It's on the mound -- specifically, in the deep group of flamethrowing relievers rumored to be up for grabs.

Here’s a look at 10 high-octane bullpen arms generating buzz ahead of the July 31 Deadline, ranked by their average fastball velocity in 2025.

All stats below are through Wednesday.

Mason Miller, RHP, Athletics

Avg. fastball velocity: 101.0 mph
Fastest pitch: 104.1 mph

With four years of team control remaining after 2025, acquiring Miller might require a bigger return package than any other trade candidate this year. The Athletics reportedly have been reluctant to even talk about him up to this point. However, The Athletic's Ken Rosenthal recently heard from sources briefed on the team’s plans who said the A’s could become more receptive to trade offers as we get closer to the Deadline. The 26-year-old righty’s 4.00 ERA this season might not turn heads, but that’s not going to deter potential suitors -- not when he ranks in the 98th percentile or better in whiff rate, chase rate, strikeout rate and expected batting average allowed; throws MLB’s fastest heater and features a slider that has held opponents to a .117 average.

Jhoan Duran, RHP, Twins

Avg. fastball velocity: 100.3 mph
Fastest pitch: 102.7 mph

Sitting at 49-53, the Twins have signaled to the rest of MLB that they are open for business. Although Minnesota’s rental players -- including Harrison Bader, Willi Castro and Danny Coulombe -- are the most likely to be dealt, the club is also reportedly willing to listen to offers for starter Joe Ryan and their closer Duran (both controllable through 2027). Going back to his rookie season in 2022, Duran leads MLB by a wide margin in pitches thrown at least 100 mph. Amazingly, though, his four-seamer isn’t even his signature pitch. That would be his 97.6 mph “splinker,” a splitter-sinker hybrid that hitters routinely drive straight into the ground. Duran’s arsenal, which also includes a knuckle curve and sweeper, has helped him generate a 31.7% whiff rate (90th percentile) and a 68.3% ground-ball rate (100th percentile) in 2025, a combination that has made him one of the most effective late-inning arms in the game. Duran has given up only five extra-base hits all season, and the homer he allowed to Shohei Ohtani on Wednesday was the first he gave up since June 21 ... in 2024.

Seth Halvorsen, RHP, Rockies

Avg. fastball velocity: 100.1 mph
Fastest pitch: 103.3 mph

In the midst of a season that could end with them breaking the record for the most losses in MLB history (set by the White Sox at 121 in 2024), the Rockies need to be considering any moves that help restock their talent pool. That includes trading Halvorsen, a 25-year-old rookie who has been serving as Colorado’s closer. Halvorsen has a 5.02 ERA and a 1.94 K/BB ratio in 2025, but other teams could be intrigued by his stuff and how it might play up at lower altitudes. Only Miller has touched 100 mph more than Halvorsen this year. Victor Vodnik, another young Colorado flamethrower who has maxed out at 101.8 mph in 2025, is also a candidate to move.

Ryan Helsley, RHP, Cardinals

Avg. fastball velocity: 99.0 mph
Fastest pitch: 103.4 mph

As the Cardinals slip further out of the NL Wild Card race, the chances of them selling at the Deadline continue to increase. That said, the no-trade clauses in the contracts of Sonny Gray, Nolan Arenado, Willson Contreras and Miles Mikolas may make it difficult for St. Louis to extensively reshape its future this summer. With those four players expected to stay put, the Cards will likely focus on moving the few pending free agents they have on the roster, a group headlined by Helsley. The 31-year-old has taken a step back after winning NL Reliever of the Year honors in 2024, but it’s tough to argue with his upside when he throws as hard as he does and has a slider that has limited hitters to a .082 average in 2025.

Emmanuel Clase, RHP, Guardians

Avg. fastball velocity: 98.9 mph
Fastest pitch: 102.0 mph

After a rough showing last October, Clase stumbled out of the gate this year, raising fresh concerns about the reigning AL Reliever of the Year. However, he has looked more like his typical self in his past 35 appearances, notching a 1.26 ERA with 38 K’s over 35 2/3 innings. With one guaranteed year (at $6 million in 2026) and a pair of $10 million club options remaining on Clase’s contract, the Guardians might not be in a rush to trade the 27-year-old, whose ability to fire his cutter in the triple-digits makes him a rare breed -- even in an era overflowing with power arms. But Cleveland could consider it for a package that helps address the organization’s perpetual offensive woes.

Seranthony Domínguez, RHP, Orioles

Avg. fastball velocity: 97.8 mph
Fastest pitch: 100.1 mph

While Félix Bautista's right shoulder injury removes the 6-foot-8 righty from trade consideration, the Orioles still had plenty of heat to offer contenders, with pending free agents Domínguez and Gregory Soto (96.7 mph fastball average) on the trade block. While the lefty-throwing Soto is en route to the Mets, Domínguez should draw significant interest, and not just because he throws hard. The right-hander’s two main secondary offerings -- a sweeper and a splitter -- have been virtually untouchable this season, combining for a 53.1% whiff rate, a 50.0% strikeout rate and a .121 opponents’ batting average. He also brings his share of postseason experience to the table and won’t be overly costly as a rental piece. All of that should be enough for contenders to overlook his elevated walk rate (14.5%).

Pete Fairbanks, RHP, Rays

Avg. fastball velocity: 97.3 mph
Fastest pitch: 100.2 mph

The Rays remain in the thick of the AL Wild Card race and have a run differential (+64) that suggests they are closer to contender than pretender. But with the way the franchise operates, always keeping one eye on the future, a Trade Deadline sale involving players on shorter-term deals can’t be ruled out. Fairbanks, who has a 2026 club option but can become a free agent after that, is one of those players. The 31-year-old’s K/9 is just 7.6 this season, a far cry from his 12.9 K/9 across 2019-23, but that hasn’t stopped him from posting a 2.84 ERA with a 2.93 FIP and 17 saves over 39 games.

David Bednar, RHP, Pirates

Avg. fastball velocity: 97.1 mph
Fastest pitch: 99.3 mph

On the heels of a 5.77 ERA in 2024, Bednar lasted just three appearances in the Majors this season before the Pirates saw it fit to option him to Triple-A. However, since returning to the Bucs on April 19, Bednar has recaptured the peak form he showed while earning back-to-back All-Star selections in 2022-23. In 36 appearances since being recalled, Bednar has posted a 1.59 ERA and a 1.50 FIP with 14 saves in 14 chances. Set to hit free agency after 2026, Bednar is one of a number of Pirates circulating in the rumor mill, along with starter Mitch Keller, third baseman Ke'Bryan Hayes and even center fielder Oneil Cruz.

Cade Smith, RHP, Guardians

Avg. fastball velocity: 96.4 mph
Fastest pitch: 99.6 mph

Smith is a trade candidate for the same reason as Clase -- the Guardians need offense, and dealing one of their star relievers is the best way to get it. The 26-year-old Smith, who comes with even more control (through 2029) than Clase, owns a 2.35 ERA with a 1.64 FIP and a 12.7 K/9 since debuting last year. His four-seam fastball has been at the heart of his success, ranking as the single most valuable pitch (+32 run value) thrown by a reliever in that time. (Clase’s cutter is second.)

Griffin Jax, RHP, Twins

Avg. fastball velocity: 96.4 mph
Fastest pitch: 98.2 mph

While Jax throws hard, his success is predicated more on getting hitters to swing at junk than on blowing them away with heat. With his sweeper and changeup doing a lot of the heavy lifting, Jax ranks in the 100th percentile in chase rate, the 98th percentile in whiff rate and the 98th percentile in strikeout rate this season, similar to what he did during his breakout 2024 campaign. Controllable through 2027 like Duran, the 30-year-old Jax would be a nice consolation prize if the Twins put a prohibitive price tag on their closer.