Bullpen trade candidates for the Mariners
Seven relievers capable of providing a boost to Seattle's bullpen.
Over the last month, we’ve discussed potential first base trade targets, the notion of a fan favorite returning to the Emerald City, and five hitters I like for the Mariners. Now, let’s turn our attention to Seattle’s bullpen.
It’s easy to compile a list of 30-or-more candidates. But with so many clubs on the edge of contention, it’s difficult to know how many of these fringe contenders will be sellers prior to the MLB trade deadline on July 31. So, I took a shot in the dark. I identified players from three teams with losing records, plus a reliever currently pitching for a wild card rival to Seattle. We’ll get to him later.
Let’s begin with a closer who didn’t get a chance to pitch against the Mariners because his club was shut out three consecutive times by Seattle’s staff. Please note that all stats are from the first half of the season.
David Bednar, RHP - Pirates
Selling points: Pitching for a club buried in the NL Central basement has kept Bednar from closing games on a regular basis. But when called upon, he’s a perfect 13 for 13 in save opportunities.
Bednar’s strikeout rate ranks 15th of 197 relievers with 25 innings. Not only that, his 27.7-percent strikeout-to-walk ratio is twelfth best within the same subset.
The curveball thrown by Bednar has held hitters to a .193 wOBA this season. That’s 14th best among 103 pitchers who’ve thrown 100 curveballs.
Bednar’s four-seam fastball averages 97.1 mph, which is 25th best among relievers who’ve thrown 200 four-seamers. The only Mariners with a higher velocity than Bednar are Andrés Muñoz (98.8 mph) and Carlos Vargas (97.8).
Potential concerns: Bednar’s high strikeout and low walk rates help minimize contact. But when opponents do hit the ball, they’ve produced a 10.7-percent barrel rate that is 27th highest among 187 relievers with 75 batted balls.
It’s not necessarily a problem. But Bednar’s reverse platoon splits are noteworthy.
Bednar’s Reverse Platoon Splits (2025)
v RHP .266 AVG, .304 OBP, .453 SLG
v LHP .182 AVG, .262 OBP, .200 SLG
Thoughts: The NL Reliever of the Month for June would be a great pickup for the Mariners or any contender. His late-inning experience would complement Seattle’s current group of high-leverage arms - Muñoz, Gabe Speier, and Matt Brash.
Yennier Cano, RHP - Orioles
Selling points: Cano’s AVG, OBP, and SLG aren’t good. Neither is his 4.68 ERA and 1.44 WHIP. But there appears to be more to the story than what the 6-foot-4 hurler’s conventional stats suggest. First, he’s been significantly better away from Camden Yards.
Cano’s Home/Away Splits (2025)
Home - .357 AVG, .403 OBP, .529 SLG
Away - .196 AVG, .274 OBP, .304 SLG
Furthermore, Cano’s .288 xwOBA is 50th-best. The only Mariner relievers with a better xwOBA than the 2023 All-Star are Speier (.254) and Muñoz (.276).
Expected Weighted On-Base Average (xwOBA) uses quality of contact (exit velocity and launch angle) to determine what should’ve happened to batted balls. A key advantage to xwOBA is defense (good or bad) doesn’t influence it. This gives us a truer sense of how a hitter or pitcher is performing. MLB league-average xwOBA for relievers = .320
Essentially, Cano’s better-than-average strikeout, walk, hard-hit, and barrel rates are driving his excellent xwOBA. Therefore, I feel better about his suboptimal triple-slash.
Something else caught my eye. Opponents are hitting .292 on ground balls surrendered by Cano. Last season, batters facing the Cuban produced a .242 AVG on grounders. Plus, there’s a large difference between Cano’s home and away AVG.
Cano’s AVG on Ground Balls (2025)
Home - .325
Away - .176
MLB AVG on ground balls = .245
It’s worth noting the Orioles’ staff has a 28th-ranked .270 AVG on grounders at home and a middle-of-the-pack .247 AVG away from Baltimore.
Cano has averaged 71 appearances and 66 innings over the previous two seasons. Moreover, he’s never been on the IL according to Baseball Prospectus and Spotrac.
Potential concerns: Perhaps the data I’m relying on to advocate for Cano has led me astray. After all, the Orioles optioned him to the minor leagues for about 10 days at the end of June.
Thoughts: Despite his minor-league demotion, I’ll go out on a limb and say Cano would be a great addition to Seattle’s stable of late-inning arms.
Danny Coulombe, LHP - Twins
Selling points: Up to the All-Star break, 455 pitchers had allowed 50 batted balls. Just one had a barrel rate lower than Coulombe’s 1.5-percent - Houston’s Shawn Dubin. Coulombe also has the sixth lowest SLG with Muñoz (.172) atop the leaderboard.
Among 67 southpaw relievers facing 50 right-handed hitters, Coulombe’s .152 AVG versus righty bats is third best behind a prominent duo - Aroldis Chapman (.139) and Josh Hader (.148).
Potential concerns: A left forearm extensor strain suffered in early May sidelined Coulombe for a month. It’s the first arm-related injury the Texas Tech product has experienced since a 2020 surgery to remove bone chips from his elbow.
Thoughts: A recent forearm injury is hard to ignore. Furthermore, an argument could be made that Coulombe’s presence would be an unnecessary redundancy since the left-handed Speier has been equally effective as the 25th round pick. Still, his domination against right-handed hitters and the ability to avoid punishing contact make Coulombe an attractive option to consider.
Pete Fairbanks, RHP - Rays
Selling points: Like Coulombe, Fairbanks has been stingy with quality contact. The Missouri alum has allowed just one home run to 150 batters. Moreover, Fairbanks’ 1.9-percent barrel rate is fourth-lowest, while his SLG and xwOBA are top-30.
Potential concerns: Fairbanks has an extensive injury history that includes shoulder, arm, hip, and back issues. This year is the first time since 2020 he hasn’t been hurt. The 31-year-old went to the IL twice in 2021, 2022, and 2024 and once in 2023.
Thoughts: Considering the Rays are right behind the Mariners in the wild card standings, discussing Fairbanks may seem like a bit of a reach. True. But Tampa Bay won just four of its final 15 contests leading up to the All-Star break. If by some chance Fairbanks’ club craters and he’s made available, his arm could be in demand.
Caleb Ferguson, LHP - Pirates
Selling points: Ferguson has also been superb at avoiding hard and quality contact. He boasts the lowest hard-hit rate and the fifth-best barrel rate. The lone lefty ahead of Ferguson is Dodgers reliever Jack Dreyer.
To this point, Ferguson hasn’t surrendered a home run to the 160 hitters he’s faced. In fact, the last four-bagger he allowed was last August 5 as an Astro.
Potential concerns: Ferguson has logged 40 innings this year, just 20.1 fewer than his personal best for any MLB campaign. To be clear, he’s previously thrown more innings in a year during his professional career. But not since undergoing Tommy John surgery in 2021.
Thoughts: Ferguson’s ability to keep the ball in the park would benefit a Mariners bullpen with an average-ish .385 SLG.
Griffin Jax, RHP - Twins
Selling points: Jax also strikes out a ton of hitters and minimizes walks. He ranks seventh in strikeout rate, while his 32.2-percent strikeout-to-walk ratio is third best just behind Hader (33.7) and Chapman (33.6).
Availability has been a strength for Jax. Since becoming a full-time reliever in 2022, he’s averaged 69 appearances and the same number of innings. In 2025, he’s on a similar pace with 40 games and 41.1 frames.
Potential concerns: This year, 58 relievers have faced 100 batters after the seventh inning. Only seven of them have allowed a higher SLG than Jax has (.455).
Thoughts: Jax has been a workhorse for the Twins over the past four years. That said, the Air Force Academy product’s late-inning SLG alarms this nerd.
Dennis Santana, RHP - Pirates
Selling points: Santana has been superb at preventing hitters from reaching first base. The Dominican Republic native’s opponent OBP is one of the five lowest, while his SLG is 14th best.
Santana has been amazing against left-handed hitters. Of the 274 right-handed arms facing 50 lefty bats, none has a lower SLG than the eight-year veteran. In 58 plate confrontations, he’s allowed just five hits - all singles.
Potential concerns: Santana is on my radar thanks to what he’s done as a Pirate. But a review of his numbers prior to arriving in Pittsburgh 13 months ago reveals he didn’t enjoy similar success elsewhere.
Santana’s Turn for the Better
Elsewhere - 5.34 ERA, .244 AVG, .343 OBP, .373 SLG
Pittsburgh - 2.02 ERA, .188 AVG, .238 OBP, .285 SLG
Would Santana revert to his former self if dealt by the Pirates? Or, does the strong performance he’s delivered with his current club follow him?
Santana has the 18th highest fly ball rate among relievers. Yet, his .112 SLG on fly balls is the lowest among peers with 100 batted balls allowed. But is this just randomness? His career SLG on fly balls prior to this season was .621.
Thoughts: It’s reasonable to wonder whether Santana’s newfound success in the Steel City would be transferable to another town. But at the very least, his late-inning effectiveness in 2025 piques my interest.
Finally
If I had to choose, my pick from the left side would be Ferguson. If not for his injury this season, my first choice would’ve been Coulombe. From the right side, I’d go with Cano.
What can I say? The numbers I rely on suggest to me Cano can deliver better outcomes than what his Baseball Reference page says he’s produced thus far. Time will tell whether my faith in those metrics was well founded or a big swing & miss.
My Oh My…