Mariners position analysis: Will bullpen improve in 2025?
For as healthy as the Seattle Mariners starting pitching was this year — Seattle’s starters were remarkably durable, leading the majors in innings, quality starts and ERA — injuries turned into a main storyline for the bullpen.
The Mariners entered spring training believing they had a formidable trio of late-inning options. They left spring training with only Andres Muñoz still standing among that group.
Matt Brash had Tommy John surgery in early May and Gregory Santos missed the vast majority of the season with back and arm injuries.
The Mariners tried to shore up the back end of the bullpen at the July trade deadline, acquiring proven veteran Yimi Garcia from Toronto. But Garcia made just nine appearances for the M’s before being shut down on Aug. 23 with an elbow injury.
It was that kind of season for Seattle’s bullpen, whose uneven performances were an underrated factor to the Mariners’ summer collapse.
There is some encouraging news for the bullpen going into 2025, though.
Brash, working out at the team’s facility in Arizona this fall, is ahead of schedule in his recovery from elbow surgery, and the Mariners are optimistic he could return to the bullpen by the end of April.
One other intriguing young arm has emerged as a viable candidate to make the Mariners’ opening-day roster: Brandyn Garcia.
A 24-year-old left-hander, the 6-foot-4 Garcia was the Mariners’ 11th-round draft pick in 2023 out of Texas A&M, where he pitched exclusively out of the bullpen.
In a year and a half, Garcia has emerged as one of Seattle’s top starting pitching prospects, earning the organization’s minor-league co-pitcher of the year honor (along with right-hander Michael Morales) and joining Logan Evans as out-of-nowhere pitching prospects from late in the 2023 draft.
In 27 appearances (25 starts) between High-A Everett and Class AA Arkansas this year, Garcia had a 2.25 ERA with 134 strikeouts, 47 walks and just four homers allowed across 116 innings.
Long term, Garcia could still be an option as a starter, but the Mariners project him as a valuable left-handed reliever in 2025, and his transition to the big-league bullpen will be one of the more interesting storylines during spring training.
Here’s where things stand around the rest of the Mariners bullpen this offseason:
Depth chart
RHP: Andres Muñoz, Matt Brash, Collin Snider, Trent Thornton, Troy Taylor, Eduard Bazardo, Gregory Santos, Cody Bolton, Blas Castano, Carlos Vargas, Jackson Kowar, Hunter Cranton
LHP: Gabe Speier, Tayler Saucedo, Brandyn Garcia, Austin Kitchen
Key number
1.7 — The Mariners bullpen ranked 26th out of 30 MLB teams with a 1.7 FanGraphs WAR, a steep decline from 2023 (5.5 fWAR) and the lowest fWAR for Seattle’s bullpen over a full season since 2019.
Key offseason question: Who emerges?
Key quote: “Our pitching is how we’re built. I love our rotation. I think we have the potential for a dynamic back end of our bullpen a year from now — or I should say, months from now.” — Jerry Dipoto in late September
Overview
Because the starting rotation was so good for so long, the Mariners needed just 490.1 innings from their relievers in 2024, by far the fewest in MLB this year and the fewest by any bullpen over a full season since 2018.
The surface-level numbers were strong: The Mariners ranked among MLB’s top 10 bullpens in ERA (3.71, ninth), strikeout rate (25.9%, fourth) and batting-average against (.213, second).
But the seventh and eighth innings — those vital swing stretches to bridge the gap to Muñoz in the ninth — were too often unpredictable.
The Mariners had a 4.67 ERA in the seventh inning, among the worst in MLB, and only one team allowed more home runs than the Mariners (28) in the eighth inning.
Brash was sorely missed. The talented right-hander was one of baseball’s best swing-and-miss relievers in 2023, when he led MLB with 78 appearances, and the Mariners are hopeful he can return to form in ’25.
On Friday, the Mariners announced they had non-tendered right-handers Austin Voth and JT Chargois, saving the club about $4 million in their projected salaries. (They also non-tendered third baseman Josh Rojas and utility man Sam Haggerty.)
The Mariners are exploring the free-agent market to potentially sign an affordable veteran reliever this winter, per sources.
Muñoz was a bright spot this year.
In his first full season as a closer, Muñoz was one of the game’s best ninth-inning arms, converting 22 of 27 save chances and earning his first All-Star selection. From July 5 to Aug. 14, he did not allow a hit over 12 consecutive appearances (12.1 innings), a franchise record.
Muñoz, who turns 26 in January, is under contract for $2.5 million in 2025, making him one of the better bargains in baseball. (The Mariners hold club options on Muñoz valued at $6 million, $8 million and $10 million over the following three years.)
In Brash’s absence, Trent Thornton became a valuable workhorse, leading the team with 71 appearances. Per Statcast metrics, Thornton has one of the most valuable sweepers in MLB, and he’s a big part of the Mariners’ plans for 2025.
A handful of others figure to be staples in the ‘pen again next season.
Troy Taylor, called up for his MLB debut in August, had an impressive 25-to-7 strikeout-to-walk ratio over 19.1 innings.
Collin Snider emerged as another hidden gem in the season’s second half, finishing with a 1.94 ERA in 42 appearances.
Injuries and underperformance marred Gabe Speier’s 2024 season, but he was one of the team’s most dependable relievers in ’23 and the Mariners are hopeful he can get back there in ’25. Tayler Saucedo remains another proven option from the left side.
Santos is a wild card. In his first year with the club, the big right-hander missed the entire first half of the season with a lat strain, then landed on the IL again late in the season with biceps inflammation, ultimately appearing in just eight games. Realistically, the Mariners probably can’t rely on him as a legitimate back-end option.
Another young right-hander to watch for: Hunter Cranton, the Mariners’ third-round draft pick this summer out of Kansas. Cranton has the best fastball in the system and is projected to rise quickly — with a potential major league call-up at some point in 2025.