The Mariners have become a playoff contender in recent years thanks in large part to their pitching. Between Logan Gilbert, George Kirby, and Bryan Woo, the club has a plethora of effective homegrown starters. With Luis Castillo also in the mix, Seattle’s rotation is both a top-10 unit in the league and well-suited to take advantage of the pitching-friendly dimensions of T-Mobile Park.
Understandably, the club is exploring ways to keep that group intact, with Daniel Kramer of MLB.com reporting that the team explored extensions with Gilbert and Woo over the offseason. Kramer adds that the talks with Gilbert did not progress to the point where the two parties were close to an agreement. Talks with Woo’s representatives were also preliminary.
Gilbert has been a staple of the rotation since debuting in 2021. In 840 2/3 innings, he owns a 3.59 ERA, a 26.2% strikeout rate, and a 5.3% walk rate. He has always done well at limiting walks, and the strikeouts have improved year over year since 2022. He is also quite durable, with 2025 being the first time he went on the injured list. After missing seven weeks with a right elbow flexor strain, Gilbert returned in mid-June and was his usual self for the rest of the season. He ultimately made 25 starts with a 3.44 ERA and a career-high 32.3% strikeout rate.
Woo, 26, made his debut in 2023 and has a 3.21 ERA through 70 career starts. Like Gilbert, Woo gets strikeouts at an above average rate and excels at limiting free passes. He has made a few trips to the IL, including two separate stints in 2024 which limited him to 22 starts. He made 30 starts for the first time in 2025. His 21 quality starts in 2025 tied Hunter Brown and Cy Young winner Tarik Skubal for fourth place in the majors. Although he missed the last two weeks of the regular season with pectoral inflammation, he returned as a reliever in the ALCS and is fully healthy heading into his first start of 2026.
Both Gilbert and Woo are immensely valuable to the Mariners, so it makes sense for the team to explore extensions while they have multiple seasons of club control remaining. Gilbert has the longer track record, with over four years of effective pitching on his resume. Being closer to free agency, an extension for Gilbert would also be more costly. Looking around the league, Garrett Crochet was the most recent starter with four to five years of service to be extended. He got six years and $170MM from the Red Sox in March 2025. Crochet’s case was unique, as he had been a reliever until 2024 and only had one (very effective) season as a starter before signing the extension.
Gilbert does not strike out as many hitters as Crochet and profiles as a No. 2 starter rather than a true ace. The recent Pablo Lopez and Mitch Keller contracts may be closer comparisons based on talent level and age at the time of signing. Lopez was worth 8.5 fWAR over 84 starts from 2019-22. He got a four-year, $73.5MM deal from the Twins in April 2023, which covered his age-28 through 31 seasons and bought out three free agent years. Meanwhile, Keller was worth a combined 6.2 fWAR in 91 appearances (89 starts) for the Pirates from 2020-23. His February 2024 extension gave him $71.6MM in new money over four years (age-29 through 32), including three free agent years.
Gilbert’s talent level puts him closer to Lopez and Keller than Crochet. Given his comparable age and superior talent, Gilbert might be worth $85-90MM over a four-year term. It wouldn’t be out of character for the Mariners to pay that amount. Castillo’s extension in 2022 gave him a similar average annual value over his age-30 to 34 seasons, and he had a comparable track record at the time to Gilbert’s now.
If the Mariners would prefer to spread money around to different parts of the roster, then Woo might be the more logical long-term fit. He is currently 26 years old and under club control through 2029. For players with two to three years of service time, Cristian Javier and Tanner Bibee are the best points of comparison. Prior to his February 2023 extension, Javier was worth a combined 4.0 fWAR over 66 appearances, roughly half of which were starts. He earned a $64MM guarantee over five years (two would-be free agent years) for an AAV of $12.8MM.
More recently, Bibee got around $47.2MM on a four-year extension in March 2025, which covered at least one free agent year. That came following a 2023-24 stretch in which Bibee accumulated 6.3 fWAR over 56 starts. Being a full-time starter, Woo is a closer match with Bibee’s contract than Javier’s. Bibee had exactly two years of service when he signed his deal, whereas Woo has closer to three years of service. The two are comparable in terms of overall performance, with Woo having an edge on a rate basis and Bibee covering slightly more innings. Based on those circumstances, Woo might garner $55MM over a four-year term ($13.75MM AAV).
Kramer framed both sets of extension talks as preliminary, so Mariners fans should take the news with a grain of salt. Nonetheless, these comparisons offer insight into how much it would cost for the club to retain their starters throughout their window of contention. Per RosterResource, the club has four guaranteed salaries on their books in 2027. Castillo ($24.15MM), Julio Rodriguez ($20.19MM), Josh Naylor ($17.3MM), and Cal Raleigh ($13.67MM). That’s a total of $75.31MM in guaranteed money. After factoring in the arbitration class, that should leave enough room for the club to extend at least one of its homegrown starters, and perhaps more.
Photo courtesy of Steven Bisig, Imagn Images
