The Seattle Mariners just watched Jorge Polanco walk to the New York Mets, and now the front office is on the clock. A response feels inevitable - and if history tells us anything about how Jerry Dipoto operates, it’s likely to come via trade rather than free agency.
Seattle has reportedly kept tabs on players like Ketel Marte and Brendan Donovan, both of whom would fill the Polanco-sized hole in the infield. But to land a difference-maker, you’ve got to give something up. So let’s take a closer look at the Mariners’ most valuable trade chips - the players who could headline a deal if Dipoto decides to swing big.
5. 2B Cole Young - A Rough Start, But Still Intriguing
Cole Young’s rookie season was a mixed bag, and that’s putting it generously. In 77 games, he posted a 78 OPS+ and 0.5 rWAR, struggling to find consistency at the plate and in the field. His year was bookended by slumps, and his defense never quite settled in.
But here’s why teams will still be calling about him: he’s just 22, was a first-round pick in 2022, and still carries the pedigree of a top-50 prospect. Young had a .388 OBP over four minor league seasons, showing advanced plate discipline and on-base skills.
He’s under team control through 2031, making him a long-term asset with bounce-back potential. If Seattle decides to include him in a deal, it won’t be without careful consideration - but he’s far from untouchable.
4. RF Lazaro Montes - Power That Turns Heads
Lazaro Montes has already been linked to Brendan Donovan in trade rumors, and it’s easy to see why. There’s some swing-and-miss in his game, and he’s not going to win any Gold Gloves in right field. But when you can hit like this kid can, teams are willing to overlook a few rough edges.
Montes mashed 32 homers in the minors this year, showcasing the 65-grade power that has scouts buzzing. He’s now ranked as MLB Pipeline’s No. 29 overall prospect, and comparisons to Yordan Alvarez - while lofty - aren’t without merit.
He’s got raw juice and just enough plate discipline to suggest he could be more than just a slugger. If the Mariners move him, they better be getting a proven big-league bat in return.
3. LHP Kade Anderson - No Pro Innings Yet, But Big-Time Upside
Kade Anderson hasn’t thrown a pitch in pro ball yet, but that hasn’t stopped the hype train. Taken No. 3 overall in July, Anderson is already viewed as one of the top left-handed pitching prospects in the game - second only to Miami’s Thomas White, according to MLB Pipeline.
What makes Anderson special? Four above-average pitches, plus control, and a track record of dominance at LSU, where he posted a 239-to-55 strikeout-to-walk ratio over two seasons.
The Mariners believe there’s another gear waiting to be unlocked once he gets into their strength and conditioning program. Anderson’s ceiling is sky-high, and while he’s not a short-term answer, he’s the kind of prospect that could headline a blockbuster.
2. SS Colt Emerson - The Crown Jewel of the Farm
Colt Emerson is the name that makes Mariners fans nervous in any trade rumor - and for good reason. He’s their No. 1 prospect, a top-10 prospect league-wide, and he’s already knocking on the door of the majors.
At just 20 years old, Emerson has made it to Triple-A, all while posting a .398 OBP and playing increasingly sharp defense. He’s even got a shot to win the third base job in spring training.
If the Mariners are serious about landing a star like Ketel Marte - someone with an estimated $100 million in surplus value - Emerson might have to be on the table. But make no mistake: it would take a massive return to pry him loose.
1. RHP Logan Gilbert, RHP George Kirby, RHP Bryce Miller - The Big Three
Here’s where things get interesting. Technically, this is a top-five list, but this spot includes three names - and for good reason. Gilbert, Kirby, and Miller are the backbone of Seattle’s rotation, and while it’s unlikely all three are available, it’s not impossible that one could be moved in the right deal.
Bryce Miller is the youngest of the group in terms of service time, with four years of club control remaining. He was Seattle’s most valuable pitcher in 2024, but a bone spur in his elbow led to a step back in 2025.
George Kirby and Logan Gilbert each have fewer years of control - three and two, respectively - and both dealt with injuries this past season. Kirby missed time with shoulder inflammation, while Gilbert was sidelined by a flexor strain. But before that, both were All-Stars and Cy Young contenders, with Kirby shining in 2023 and Gilbert following up in 2024.
Baseball Trade Values puts Kirby’s surplus value at $71.8 million, Gilbert’s at $44.4 million, and Miller’s at $30.9 million. Depending on the team, preferences will vary - some might value Kirby’s command, others might bet on Miller’s upside.
The real challenge is convincing Dipoto to part with one of his homegrown arms. Historically, he’s been reluctant to do so.
Honorable Mention: RHP Ryan Sloan - A Name to Watch
Ryan Sloan isn’t quite a household name yet, but he’s trending in that direction. Drafted in the second round in 2024, the 19-year-old right-hander impressed in his first full pro season. Over 21 starts across Single-A and High-A, Sloan struck out 90 and walked just 15 in 82 innings - elite command for someone his age.
He’s not in elite prospect territory just yet, but the tools are there. If he stays healthy, Sloan has No. 1 starter upside. He’s more of a long-term piece, but he could be an intriguing sweetener in a larger deal.
Bottom line: The Mariners have options - real, valuable ones - if they want to make a splash on the trade market. Whether they’re willing to part with one of their top arms or a blue-chip prospect like Emerson remains to be seen. But if they want to keep pace in a loaded AL West, standing still isn’t an option.