The Mariners’ Bullpen Blueprint: Trade Fits – Part Two

The Seattle Mariners’ bullpen construction is not accidental. Each pitcher has a defined role within the unit. They all fit into a clear blueprint that shows what the Mariners prioritize when acquiring bullpen arms: a high-velocity fastball, primarily a two-pitch mix leaning either slider or sinker, high zone%, lots of ground balls, low-quality contact, and a low walk rate.

It is no secret that the Mariners are not done yet. They believe they can keep building on an already formidable unit. Having come so close in last year’s ALCS, they ultimately came undone. Pitchers such as Gabe Speier and Eduard Bazardo, who were reliable all year, became overworked as opposing lineups saw them too often in seven-game sets.

The Mariners acquired every arm in their bullpen going into 2026 via trade. They have a clear identity and have proven to be aggressive in targeting arms they believe will be a good fit.

The addition of another lefty this winter, in José Ferrer, who perfectly fits their middle-reliever profile, is huge. Now they will keep looking for another righty to add to the mix. Using this framework, we can establish parameters and identify bullpen arms that fit the Mariners’ profile.

This is where data can really help teams identify arms that fit their club, ballpark, and roster construction. Building on the bullpen traits and characteristics outlined in Part One, the analysis evaluates Mariners trade candidates against the six criteria below.

The Criteria

1. Fastball ≥ 95 mph
2. Primary two pitches account for ≥ 70% usage
3. Walk rate ≤ 10% or K-BB% ≥ 15%
4. Either: Ground-ball rate ≥ 50% or Whiff rate ≥ 30%
5. Barrel rate ≤ 9%
6. Zone% ≥ 50%

Disclaimer: None of the pitchers below has been linked to the Mariners. The selection is based solely on trade fits for the Mariners’ bullpen profile and team context.

1. Juan Mejia (COL)

With the Colorado Rockies projected to have a league-worst 66 wins and on the cusp of another 100-loss season, they are natural trade partners. They also happen to have some bullpen arms that, while not suited to the pitcher graveyard that is Coors Field, could fare much better in a system designed to suit their abilities.

Juan Mejia is a very interesting pitcher. What immediately jumps out is a straight two-pitch mix: a four-seam fastball thrown 67% of the time in 2025 and a slider at 33%. His fastball sits at 96 mph on average, and his slider shows 8.3 inches of above-average horizontal movement with nearly 14 inches of glove-side movement. Throwing this many fastballs and such live sliders, his Zone% sits at 53% and his whiff rate at 30.4%. This falls in the Matt Brash archetype.

This is a pitcher with elite swing-and-miss potential sitting on a team not designed to help him reach that potential. Similar to how Ferrer’s ground-ball profile was muted in a hitter-friendly ballpark, Mejia’s fastball-heavy approach could play up significantly outside of Coors. What is key with this profile is his ability to limit hard contact even when throwing so many fastballs. His fastball spin ranks in the 98th percentile, which helps keep his barrel rate below 5% (92nd percentile). At 25 years old, the slider is the pitch that could take a step forward. The Mariners have a track record of developing sliders as well as anyone in baseball and could even help him by adding another pitch into his mix to keep batters off balance.

This is the raw, high-upside arm the Mariners love, fitting the high velocity and swing-and-miss blueprint.

2. Graham Ashcraft (CIN)

Despite making the playoffs last year and adding some notable pieces such as Eugenio Suarez, the Cincinnati Reds are projected to have a losing record in 2026. It is a real possibility that they look to stockpile prospects at the trade deadline, making them strong candidates to move bullpen arms.

Entering his fifth season, Graham Ashcraft put up an impressive 2025 campaign. Similar to Mejia, he relied on two pitches: a cutter and a slider. While Mejia falls into the Brash Whiff% rate archetype, Ashcraft fits much more into the Ferrer, Vargas ground-ball profile. He possesses outstanding velocity on both his cutter (97 mph) and his slider (89 mph), with the slider also featuring a strong movement profile and +seven run value. While plus-slider pitchers are usually associated with swing-and-miss, Ashcraft’s GB% sits near 60% (96th percentile), while Hard-Hit% and Barrel% are in the 96th and 97th percentiles, respectively. This is the exact profile the Mariners have identified, particularly at home, where keeping the ball on the ground and in the park is at a premium.

The Mariners have shown they are the organization for slider-dominant pitchers and would utilize Ashcraft’s skill set to the fullest. He would be a certain upgrade on Carlos Vargas and would pair well with Bazardo as middle right-hand relievers. He has the velocity and pitch arsenal to attack the zone and suppress the quality of contact at an elite rate.

3. Abner Uribe (MIL)

Admittedly, this is the most unrealistic target of the three and would likely only be available at the deadline if the Milwaukee Brewers found themselves out of the postseason picture. Even so, this is an organization with a reputation for dealing with its stars, if the cost is right. Teams do put elite closers on the market if the situation permits, with Jhoan Duran’s trade to the Philadelphia Phillies a recent example.

Abner Uribe is a Mariner pitcher — profile-wise. You could not construct an arm more perfectly aligned with the criteria set. Uribe’s pitch mix consists of a plus slider and sinker that make up 98% of his arsenal. The sinker is thrown with high velocity at 99 mph. He combines both a swing-and-miss profile and a ground-ball profile. He possesses the best Barrel% in baseball at 2.9% and a ground-ball rate above 54%. Pair this with a whiff rate north of 30% and a strikeout rate in a similar range, and you have one of the best reliever profiles not just for the Mariners, but in baseball.

His slider has more than 10 inches of glove-side sweep, and his sinker can hit triple digits, both plus pitches for generating swing and miss while suppressing contact. This is not the kind of arm that becomes available easily. The Mariners by all accounts pursued Duran aggressively at last season’s trade deadline before he went to Philadelphia, and they could take a similar approach in targeting a premium relief arm built for their bullpen this year.

Summary

These three pitchers could help any club, but the Mariners specifically have a long track record of targeting these kinds of arms. They have built this framework for a reason and have had great success implementing it. What is clear is the Mariners have one of the best bullpens in baseball, and any additions will fit this profile they have built over the course of the Jerry Dipoto era.