The Seattle Mariners have quietly emerged as legitimate contenders in the American League, but one glaring weakness remains their second base position. While they've explored internal options and external targets like Jorge Polanco and Brendan Donovan, there's one player who could transform their lineup immediately: Arizona Diamondbacks star Ketel Marte. After the winter meetings showcase teams' seriousness about moving the All-Star second baseman, the Mariners have a legitimate window to strike with a compelling offer that addresses both sides' needs.
Marte represents everything the Mariners need at the keystone position. He finished 2025 with a robust .376 on-base percentage and produced 28 home runs while maintaining elite contact rates and a well-rounded offensive profile. With five years and $91 million remaining on his contract (plus a sixth-year player option), Marte is locked in at a reasonable salary that won't strangle the franchise's financial flexibility. The Mariners can't afford another season of uncertainty at second base, and Marte provides the stability and production that separates contenders from pretenders.
What Arizona Wants and What Seattle Can Offer for Ketel Marte
The Diamondbacks have been vocal about their asking price: they want established talent, controlled-cost pieces, and depth. Seattle's proposal would center around proven ML talent packaged with intriguing young depth that Arizona can develop for immediate 2026 contribution and beyond.
Mariners Trade Package for Ketel Marte:
Mariners Receive:
- 2b Ketel Marte
Diamondbacks Receive:
- OF Victor Robles
- OF Luke Raley
- 3B Ben Williamson
The framework is straightforward. Victor Robles gives Arizona a talented outfielder with defensive excellence and speed who can immediately slot into their lineup. Robles has established himself as a capable big-league player while still being affordable relative to his production. Luke Raley represents depth and versatility with proven power potential in the outfield. He can DH or play corner positions, providing Arizona with multiple lineup configurations.
Ben Williamson is the prospect asset in this deal—a 24-year-old third baseman who offers defensive versatility and a promising offensive ceiling. The Diamondbacks have dealt away depth in recent years, and Williamson provides a developmental piece to grow with their system.
A Path Forward for Both Franchises
This proposal doesn't mortgage Seattle's future. The Mariners retain their top prospects like Colt Emerson, Lazaro Montes, Kade Anderson, and Ryan Sloan while addressing their critical second base need with a proven talent. Arizona receives established outfield depth that addresses their crowded outfield situation, a young defensive prospect, and pitching help—precisely what they've indicated matters most in any Marte trade dialogue.
The beauty of this framework is that it's palatable for both organizations. Seattle gets their centerpiece All-Star, Arizona receives multiple useful pieces to accelerate their rebuild trajectory, and neither team walks away feeling fleeced. With the winter meetings underway and Marte's availability still uncertain, the Mariners should aggressively push this proposal. The window to land the sport's best second baseman is open—they just need to make the right move.
