Analysis: Will Mariners have to trade a starting pitcher to improve offense?
SEATTLE – Don’t do it, he told them. Don’t trade away our young starting pitchers.
That was Julio Rodriguez’s message to Mariners management last offseason, and the sentiment hasn’t changed from the star center fielder a year later.
“That’s our cornerstone – that’s the team,” Rodriguez said in late September. “They keep us in the game. They keep us in the game every single time. What I would like to see, and feel like what everybody would like to see, is just more support for them.”
Can the Mariners do that – can they find a way to create greater run support for their pitchers without giving one of them up?
That’s the prevailing question for the Mariners, the backdrop that will color everything they do this offseason.
In an ideal scenario, the Mariners would like to upgrade their lineup without trading one of the five starting pitchers – Logan Gilbert, George Kirby, Luis Castillo, Bryce Miller, Bryan Woo – from a rotation that ranked as baseball’s best in several notable areas this year.
Last offseason, the Mariners decided to hang on to all of those starters despite heavy interest – for Miller and Woo, in particular – from other clubs.
But given their obvious need for a bat – and given that they missed out on the postseason for a second straight year even with one of the game’s best rotations – will the Mariners need to trade away one of their prized pitchers this winter?
Jerry Dipoto, president of baseball operations, was asked that question on the penultimate day of the season.
“On the continuum of A to Z, that would be Plan Z times some denominator,” Dipoto said. “We could shoot ourselves in the foot by trying to get too crafty in what we do. Our pitching is how we’re built. I love our rotation.”
And then he ended a long answer with a caveat.
“That wouldn’t be Plan A,” he added, “but we’ll go into every offseason open to whatever ideas might make us better.”
Industry sources have said the Mariners have positioned themselves at the beginning of the offseason as “open to anything” in potential trade scenarios.
The only option?
Major league clubs have three avenues with which to construct a roster: through the amateur draft (or amateur international signings); through free agency; or through trades with other clubs.
In the minor leagues, the Mariners have tantalizing prospects they can dream on – hitters they’ve drafted (or signed) and developed, who could join Rodriguez and Cal Raleigh as foundational pieces at some point. But the top prospects are still teenagers, and sources have said that none of them is expected to be ready to contribute in a meaningful way at the major league level in 2025.
On the free-agent front, the Mariners have signaled that they do not intend to engage in that market this winter – at least, they don’t intend to pay top dollar for the kind of difference-making bats they need.
That leaves the trade market as the only realistic option for the Mariners to improve their roster, and in that regard, Dipoto has been as active as any baseball executive over the past decade – 175 trades in all since taking charge of the Mariners front office in 2015.
Three other factors that could weigh into any trade scenarios: pitcher health, payroll constraints and pitching depth.
Arm injuries continue to be an unavoidable topic around baseball, and Mariners starters, compared to most teams, enjoyed a remarkably healthy season in 2024. Seattle was the only MLB club that had four pitchers (Gilbert, Kirby, Miller, Castillo) make at least 30 starters, and the fifth (Woo) made 22.
How long can that good health continue?
And should the Mariners mitigate some of the inherent risk by trading away a pitcher before a potential injury?
Player salaries could play a role this offseason, too. The Mariners had an incredibly affordable rotation this year, with the top six starters earning roughly $30 million combined. (Best bargain in baseball, anyone?) The Philadelphia Phillies, by comparison, paid some $73 million to their top six starters.
Seattle’s starters will start to get more expensive in 2025.
Castillo is on the books as the highest-paid player on the roster next season, at $22.75 million.
Gilbert is projected to double his salary, up to $8 million in 2025, and Kirby enters his first year of arbitration eligibility projected to earn about $5.5 million. Those are still bargain rates, but for an organization with a tight budget, could Gilbert and Kirby’s escalating costs eventually be a tipping point for a trade?
The Mariners have a strong track record of pitching development in recent years – Gilbert, Kirby, Miller and Woo serving as the best examples of that.
Right-hander Emerson Hancock, the Mariners’ first-round pick in 2020, was the team’s No. 6 starter this season, posting a 4.75 ERA over 12 starts. Could he be in a line for a larger role next season?
Right-hander Logan Evans and left-hander Brandyn Garcia had breakthrough seasons in Double-A, and Dipoto said they’re knocking on the door of a big-league promotion in the not-too-distant future. Could their development help prompt a trade from the big-league staff?
The fab five
A breakdown of the Mariners’ top five starting pitchers and why the club might (and might not) consider dealing one of them this winter:
LUIS CASTILLO, RHP
Age: 31 (turns 32 on Dec. 12)
2024 stats: 30 starts, 11-12 record, 3.64 ERA, 47 walks, 175 strikeouts, 1.17 WHIP, 175.1 innings
Contract: Due $22.75 million each season through 2027, with a 2028 vesting option. Has full no-trade clause through 2025.
Outlook: The acquisition of Castillo at the 2022 trade deadline helped spark the Mariners’ first playoff berth in 21 years, and that deal might go down as the best trade Dipoto has made in his tenure in Seattle. Soon after the trade, the Mariners locked up Castillo with a five-year, $108-million extension. Castillo has mostly lived up to the contract, earning an All-Star bid in 2023 and posting a 3.43 ERA and a 1.13 WHIP in 74 starts for the Mariners. Because Castillo is Seattle’s oldest and most expensive starter, there has been speculation that the Mariners might try to move him this offseason. But because of those same reasons – his age, his contract and his no-trade clause – an industry source said Castillo is the “least likely” of the five Seattle starters to be traded.
LOGAN GILBERT, RHP
Age: 27 (turns 28 on Dec. 12)
2024 stats: 33 starts, 9-12 record, 3.53 ERA,
Contract: Enters second year of arbitration eligibility; expected to make about $8.1 million in 2025, per MLB Trade Rumors projections.
Outlook: Gilbert joined the ranks of the best right-handed pitchers in the game this year, earning his first All-Star bid and leading MLB in innings pitched and WHIP and tying the AL lead with 22 quality starts. Do the Mariners want to trade a homegrown first-round talent at the peak of his powers? Of course not, no. But is there a potential offer out there that could entice them? Certainly. And, sure, you could say that about nearly any player on any team. What makes the situation with Gilbert a little more timely is his rising salary in arbitration and the fact that there has been little discussion about a long-term deal. Nothing is imminent in that regard, sources have said.
GEORGE KIRBY, RHP
Age: 26 (turns 27 on Feb. 4)
2024 stats: 33 starts, 14-11 record, 3.53 ERA, 23 walks, 179 strikeouts, 1.07 WHIP, 191 innings
Contract: Enters first year of arbitration eligibility; expected to make about $5.5 million in 2025, per MLB Trade Rumors projections.
Outlook: Kirby’s 2024 season was nearly identical to his 2023 season, but it did represent something of a small step back for the 2023 All-Star. Kirby still has one of the game’s most elite fastballs, and his command is as good – if not better – than any pitcher who’s lived. Taken in the first round in back-to-back years, Gilbert and Kirby are usually lumped together, and the same question asked of Gilbert does apply to Kirby: Why trade a homegrown talent at the peak of his powers? The answer is the Mariners almost certainly won’t trade Kirby, but they might be ever-so-slighly more open to the idea than they were at this time a year ago.
BRYCE MILLER, RHP
Age: 26 (turns 27 on Aug. 23)
2024 stats: 31 starts, 12-8 record, 2.94 ERA, 45 walks, 171 strikeouts, 0.98 WHIP, 180.1 innings
Contract: Prearbitration (expected 2025 salary: $798,000)
Outlook: In his first full big-league season, Miller emerged as a dependable workhorse on the mound and one of the most affable teammates in the Mariners clubhouse. He has a seven-pitch arsenal, openly advertising his new splitter last offseason and then learning a new knuckle curveball on the fly midseason. He was especially effective at home (1.96 ERA in 16 starts at T-Mobile Park), and he was at his best in his final two starts – shutting down the Yankees and Astros in a must-win game for the Mariners. What might the Mariners get in a hypothetical trade for Miller? That depends on how teams view Miller’s potential. Is he a true No. 2-type starter capable of repeating his 2024 success? Or is more of a midrotation starter who has benefited from pitching in T-Mobile Park? “It would be ridiculous for them to trade any of their starters,” one NL scout said. “But if they have to trade someone, Miller would make the most sense.”
BRYAN WOO, RHP
Age: 24 (turns 25 on Jan. 30)
2024 stats: 22 starts, 9-3 record, 2.89 ERA, 13 walks, 101 strikeouts, 0.90 WHIP, 121.1 innings
Contract: Prearbitration (expected 2025 salary: $798,000)
Outlook: After an injury scare early in the season, Woo emerged as one of the Mariners’ best stories of the 2024 season. Relying predominantly on his two fastballs, and throwing from a low arm slot, Woo held hitters to a .574 OPS, third best in MLB behind only Pittsburgh’s Paul Skenes (.552) and Detroit’s Tarik Skubal (.558); that also ranks as the third best in a season in franchise history behind Felix Hernandez (.546, 2014) and Randy Johnson (.569, 1995). Because of his injury history, it’s difficult to get a sense of how other MLB club might value Woo – and thus, it’s difficult to imagine a scenario where the Mariners get commensurate value in return. Because Woo is under club control through 2029, it’s difficult to imagine the Mariners moving him this winter.