How the Mariners Built One of the Best Teams in the American League
In late September 2025, the Seattle Mariners are in a position they haven’t seen in over two decades—leading the American League West with a realistic path to the World Series. Their transformation didn’t happen overnight, nor did it rely on splashy free-agent moves.
In fact, the change began after years of narrow eliminations and tough finishes. They’ve eventually managed to build a club that competes hard every night and rarely beats itself.
Offense Has Become Their Most Reliable Weapon
Image via Wikimedia Commons/Keith Allison
The Mariners recorded the most productive offense in Major League Baseball in September, while leading in total runs and several key batting metrics. However, their success hasn’t depended on a handful of high-profile sluggers. Instead, the team built a lineup that performs consistently throughout.
Hitters contribute in different ways—through power, contact, and situational execution. Players like J.P. Crawford, Cal Raleigh, Julio Rodríguez, and Dominic Canzone have been able to apply pressure in games and keep scoring from stalling late. This type of offensive balance has given them an advantage against a variety of pitching staffs.
Rotation Depth Provides Stability and Matchup Control
The Mariners have built one of the most reliable starting rotations in the American League, anchored by Bryan Woo, Logan Gilbert, George Kirby, and Luis Castillo, who consistently give the team quality innings. Each can handle six or more frames and ease the bullpen’s load across a series.
Woo’s health remains an ongoing question, but when available, he provides another reliable option against strong lineups. Seattle also shifted Bryce Miller to the bullpen for the postseason, a move that increases late-inning flexibility without undermining rotation depth. The combined effect allows the team to control tempo, disrupt opposing hitters, and avoid overexposing relievers in close, high-stakes games.
Bullpen Strategy Strengthens Their Playoff Outlook
Image via Wikimedia Commons/Keith Allison
There is no denying that Seattle’s bullpen is built for postseason durability. Rather than relying on a single closer or setup man, they’ve created a system with multiple arms that can enter in high-pressure moments. High-profile names include Andrés Muñoz, Caleb Ferguson, Gabe Speier, Matt Brash, Eduard Bazardo, and the newly shifted Bryce Miller.
This mix gives the coaching staff flexibility in how they manage late innings, especially in back-to-back games or extra-inning situations. The team has also avoided overuse by spreading appearances across the group. Seattle’s relievers have consistently protected leads and limited scoring in tight spots.
As postseason baseball often comes down to bullpen management, the Mariners have placed themselves in a strong position.