The Seattle Mariners came painfully close to breaking through one of the last major barriers in franchise history: reaching the World Series. After decades of chasing that elusive milestone, the 2025 postseason felt like the year when everything might finally line up. Seattle had the pitching, the defense, the timely offense, and the swagger of a team built for October. But just as their long-awaited breakthrough seemed within arm’s reach, the Toronto Blue Jays slammed the door. The Mariners fell just short, leaving fans, players, and the front office wondering what more they needed to finally get over the hump.
Now, heading into the next season, the organization knows it can’t afford to take any steps backward. The roster isn’t far off in fact, Seattle arguably possesses one of the most complete young cores in the American League. But the margin for error in the postseason is razor-thin, and the Mariners understand that if they want to go from almost-there to fully-there, they must look critically at every possible upgrade. No position can be overlooked, no opportunity ignored, and no weakness tolerated.
One area where a meaningful improvement could make a difference is second base. Jorge Polanco played well for Seattle during the 2025 campaign, especially considering the occasional injuries he battled. He provided veteran leadership, switch-hitting versatility, and stretches of above-average production. But Polanco is now a free agent, and the Mariners face a choice: invest in him again, or pivot to a more dynamic long-term solution.
According to Bleacher Report’s Joel Reuter, the answer is clear. Reuter believes Seattle should allow Polanco to walk in free agency and instead pursue a major trade that would immediately elevate the offense. His proposed target? Arizona Diamondbacks star infielder Ketel Marte, a longtime All-Star, Silver Slugger, and one of the most well-rounded second basemen in the league.
Reuter laid out a potential trade framework that he believes would be mutually reasonable for both teams:
Mariners receive:
• 2B Ketel Marte
Diamondbacks receive:
• RHP Logan Evans
• 2B Michael Arroyo
• SS Felnin Celesten
In Reuter’s assessment, the Mariners are in a uniquely strong position to pull off this kind of bold move. Their farm system is deep, loaded with infield talent and pitching depth, and they have the kind of prospect capital necessary to pry a star-level player away from a competitive team like Arizona.
One major factor fueling Marte’s trade-market buzz is his contract situation and service-time status. As Reuter notes, Marte is set to earn 10-and-5 rights early in the 2026 season. These rights — granted to players with 10 years of MLB service time and at least five consecutive years with the same team — give the player the power to veto any trade. Once Marte reaches that threshold, the Diamondbacks would lose control over his future mobility. If they wait too long and Marte decides he wants to stay in Arizona, they wouldn’t be able to move him even if they wanted to.
That dynamic creates a strategic window during which Arizona might consider offers, especially if they feel their roster needs retooling or if they want to capitalize on Marte’s immense value while they still can. As a switch-hitting infielder with power, speed, and defensive reliability, Marte’s skill set is the type that rarely becomes available.
Reuter emphasized how impactful Marte could be for Seattle’s lineup:
“Adding his impact bat at second base would give the Mariners an upgrade over Jorge Polanco, who had a strong 2025 season in his own right,” he wrote. “Seattle has more prospect talent to offer up on the trade market than any team in baseball.”
The numbers certainly support Reuter’s enthusiasm. Marte put together an outstanding offensive performance this past season, slashing .283/.376/.517/.893 across 126 games. His stat line included 28 doubles, 28 home runs, and 72 RBI, reflecting both power and consistency. At a time when switch-hitters continue to be highly valued for lineup flexibility, Marte also checks that box — meaning Seattle wouldn’t lose the platoon-balance benefit they enjoyed with Polanco.
Beyond the statistics, Marte brings something intangible the Mariners could truly use: proven postseason experience and big-moment reliability. As a key figure on Arizona’s 2023 and 2024 playoff runs — including their remarkable journey to the 2023 World Series Marte has demonstrated he can thrive under October pressure. The Mariners, who are still searching for players with deep playoff pedigree, would gain someone who carries himself like a franchise cornerstone.
Seattle, of course, would have to give up significant young talent to acquire a player of Marte’s caliber. Prospects such as Michael Arroyo and Felnin Celesten represent real future potential, while right-hander Logan Evans has the makings of a dependable major-league arm. But for a franchise in win-now mode and desperate for that final piece to push them over the edge, the price may be worth paying. Championships often require calculated risks.
Another subtle factor that may work in Seattle’s favor is their recent trade history with Arizona. Just this past trade deadline, the two teams completed a notable deal when Seattle acquired power-hitting infielder Josh Naylor from the Diamondbacks. That transaction not only helped the Mariners down the stretch, but it also established a functional communication line between the front offices. When two organizations already trust each other and have found common ground before, negotiations for a second deal can progress more smoothly.
If Seattle sees Marte as the missing ingredient to elevate their offense, this existing relationship could be essential. While nothing guarantees a blockbuster trade, the Mariners have at least laid the groundwork to engage the Diamondbacks once again. Both clubs are familiar with each other’s prospect pools, player development philosophies, and organizational needs, making the potential for dialogue more likely than it would be between two teams with no recent history.
From a roster-construction standpoint, acquiring Marte would reshape the Mariners’ infield. Marte would take over second base full-time, giving Seattle an athletic upgrade with a significantly higher offensive ceiling. His presence in the lineup would lengthen the batting order, offering more protection for star hitters like Julio Rodríguez and Josh Naylor. Mariners manager Scott Servais could also benefit from Marte’s switch-hitting bat when crafting daily matchups or late-game pinch-hitting decisions.
Meanwhile, losing Polanco doesn’t necessarily harm Seattle in the long term. Although he contributed effectively in 2025, his age and injury history make him a riskier long-term investment, especially at the price he may command in free agency. Reuter’s suggestion to let Polanco walk reflects the philosophy that teams must sometimes say goodbye to good players when better ones become available. Polanco would likely find a home elsewhere, but Seattle is in a position where settling for “good enough” is no longer acceptable.
The Mariners’ front office has already demonstrated its willingness to make bold moves whether trading for Luis Castillo, acquiring Eugenio Suárez, retooling the offense multiple times, or reshaping the bullpen. Adding Ketel Marte would be another decisive step in building a championship-caliber roster.
Ultimately, this proposed trade underscores where Seattle stands as a franchise. For years, they were rebuilding, stockpiling young talent, drafting carefully, and hoping for future success. Now, the future has arrived. The Mariners are no longer trying to become competitive they are competitive. What remains is the final ascent from playoff participant to World Series contender.
To make that leap, they must be willing to strike when opportunity calls. And if Arizona opens the door to Marte conversations, Seattle’s leadership should be ready.
In the end, the Mariners and Diamondbacks pairing again for another major deal isn’t just a possibility it might be the bold move Seattle needs to finally reach the promised land they were so close to touching last season.
