Mariners boldly bolster the bullpen

The cost was a prospect, who was a fan favorite. But acquiring Jose A. Ferrer is value added for a club with World Series aspirations.

Daniel Kucin Jr. - AP Images

The Mariners upgraded their bullpen with today’s acquisition of left-handed reliever Jose A. Ferrer from the Nationals in exchange for two prospects - catcher Harry Ford and pitcher Isaac Lyon.

Ferrer, who appeared in 72 games for Washington this year, debuted with the club in 2023 and will turn 26 in March. Let’s walk through his numbers, as we did during our most recent trade target discussion.

Selling points: Opponents had a 4.8-percent barrel rate against Ferrer, which was better than any Mariner pitcher who faced at least 100 batters. The third-year reliever’s aversion to the loudest of contact led to a 1.5-percent home run rate that was half the MLB average of 3.1-percent.

Free passes were also rare for Ferrer. Gabe Speier (4.5%) was the only Seattle hurler to best his 4.9-percent walk rate.

Ferrer was extremely effective against lefty bats. With the exception of strikeouts, the Dominican Republic native limited opponents to a slash line that was very similar to Speier’s and much better than the MLB average in nearly every category.

Ferrer’s numbers were dramatically better on the road than at Nationals Park this season. This is a plus considering where he’ll be pitching home games in 2026.

Home/Away Splits (2025)

Home: .312 AVG, .364 OBP, .426 SLG
Away: .242 AVG, .291 OBP, .340 SLG

According to Statcast’s Park Factors, Washington’s home field is baseball’s sixth most hitter-friendly venue. As I’ve noted 7,239 times this year, T-Mobile Park favors pitchers more than any location in MLB. Therefore, the change of scenery should benefit the 25-year-old next season.

This year, Ferrer generated a 62.6-percent ground ball rate. Of the 199 pitchers logging at least 70 innings, only two had a higher ground ball rate - José Soriano (65.3%) and Jhoan Duran (65%).

Ferrer brings the heat. The 6-foot-1, 233-pounder threw 25 pitches with a velocity of 100 mph-or-greater. The only Mariner to best this mark was Andrés Muñoz with 35 warp-speed offerings. Furthermore, the average velocity of Ferrer’s sinker was 97.7 mph - fifth-highest among 120 pitchers throwing 300-plus sinkers.

Although he predominantly appeared in the seventh and eighth inning for the Nationals, Ferrer has been exposed to closing games. All told, he saved 11 contests in the final two months of the 2025 campaign.

Ferrer also demonstrated the ability to pitch multiple innings this year. He recorded four-plus outs in 19 relief appearances, including five outings covering two frames.

Potential concerns: Ferrer’s .276 AVG placed 140th among 153 relievers facing at least 200 hitters, while his .310 wOBA ranked 122nd. Suboptimal results that must improve moving forward.

While Ferrer was exceptional against left-handed hitters, the same can’t be said about opponents in the other batter’s box. Right-handed bats produced a .312 AVG, .364 OBP, .426 SLG against him. For additional perspective, consider this. Ferrer’s opponent AVG was the highest of any southpaw facing 200 right-handed hitters.

Even though Ferrer’s sinker was one of the fastest in baseball, opponents managed to hit .309 against it this year. In 2024, it yielded a .227 AVG for the southpaw. Good enough for 10th best among 65 relievers throwing the pitch 250 times. It’s reasonable to wonder whether Ferrer’s sinker will rebound, regress, or remain somewhat effective in 2026.

Possible smoking gun: Ferrer’s opponent AVG and OBP are definitely unappealing. But there’s evidence worth considering when discussing a pitcher whose success is contingent on keeping the ball on the ground. His team’s infield defense was suspect in 2025.

The Nationals’ infield contingent accrued a minus-27 Fielding Run Value (FRV) - the worst in baseball. This had to factor into Washington’s .282 AVG on ground balls being the highest allowed by any team. In Ferrer’s case, opponents hit .273 on ground balls he surrendered, which was 24 points above the MLB average.

To me, a pitcher with the third highest ground ball rate in baseball with the worst infield defense behind him is bound to experience damaging results on grounders. Perhaps this is one of many factors influencing the Mariners to acquire Ferrer.

Before moving on, it’s important to note Seattle’s infield FRV was third worst. Clearly, work needs to be done to tighten up the group’s defense. Especially with a ground ball machine like Ferrer entering the mix. That said, the infield is expected to undergo a makeover and will likely look different by Opening Day than it did for the 2025 season opener.

Thoughts: The addition of Ferrer instantly makes Seattle’s bullpen deeper and better. The move also gives manager Dan Wilson another southpaw to pair with Speier, who was exceptional against left- and right-handed hitters in 2025. That said, Ferrer improving against righty bats next season would be a beneficial development to the unit’s overall success.

Assuming good health, the Mariners will have Speier, Matt Brash, Eduard Bazardo, and now Ferrer to serve as the bridge between the starter and Muñoz. An excellent foundation and it’s only December 6.

My Oh My…