Mariners Burned a Prime Year of Their Core While the AL West Fell Apart

The AL West begged to be won. The Mariners couldn’t answer the call.

Sep 20, 2026; Denver, Colorado, USA; Seattle Mariners pitcher Andres Munoz (75) pitches in the ninth inning against the Colorado Rockies at Coors Field. Mandatory Credit: Christopher Hanewinckel-Imagn Images | IMAGN IMAGES via Reuters Connect

A long season of baseball gives every disappointing team a bucket of excuses. The Mariners could actually fill two. But that wouldn’t exactly validate a bad season. They lost important players to injuries. Their biggest stars underperformed. And the rotation stopped carrying the roster. The bullpen also cracked under specific roles some arms were never built to handle.

All of that belongs in a 2026 season that has been a letdown. None of it changes the worst part of it. 

The AL West fell apart right in front of the Mariners, and they fell apart with it. A year ago, Seattle won 90 games, captured the division and came within one victory of reaching the World Series. That run was supposed to be the breakthrough. The Mariners had finally assembled a core capable of doing more than hanging around the Wild Card race and selling hope into the postseason. They followed it up with their first full losing season since 2019.

The Mariners Built a Contender That Needed Everything to Go Right

This wasn’t a case of Seattle running into another Houston Astros-like problem or an overpowering Texas Rangers club steamrolling their way toward 100 wins. The division spent the majority of the season wobbling around .500. Nobody seized control or created meaningful separation. And the Mariners weren’t forced to chase anything. They only needed to be competent for an extended stretch.

After their eight-game winning streak ended in early June, the Mariners won three consecutive games only twice. So, a team expected to contend for another division title went nearly four months without producing one serious sustained run.

Logan Gilbert understood the cost. After Seattle guaranteed itself a losing record, he talked about how quickly careers move and how rarely a talented team gets an opening like this one. We can appreciate that acknowledgement, because he’s right.

We discuss competitive windows as if they are permanent fixtures attached to a roster. Julio Rodríguez is still here. Cal Raleigh is under contract. The rotation still has recognizable names. Several highly regarded prospects have arrived and/or are on the way. Therefore, the window must remain open, right?

But that’s not how it works. A genuine window is a specific intersection of talent, health, contracts, performance and opportunity. The Mariners entered 2026 as defending division champions with a 90-win core and an AL West lacking a dominant opponent. They may have more talented teams in the future, but they cannot order these kinds of circumstances again. This was the season sitting there for them and they burned it down.

Mariners Injuries Exposed a Roster With No Margin for Error

We can point to some of the injuries that were substantial. Brendan Donovan barely played. Matt Brash made only 20 appearances. Carlos Vargas missed most of the season. Raleigh, J.P. Crawford and Luke Raley also lost time.

But injuries don’t erase the larger problem with their roster construction. They simply expose it. The Mariners were constructed to work if the rotation remained elite, the stars produced and a small number of high-leverage relievers, and support bats stayed healthy. Once two or three of those assumptions failed simultaneously, they had no safety net. They just continued to rotate castoffs on the waiver wire.

When the lineup disappeared, the rotation could no longer suffocate every opponent. When the starters stopped pitching deep into games, the bullpen couldn’t absorb it. 

Good teams survive a problem. It says a lot about how Seattle needs everything to work at once to win a ballgame. It’s far from what you can call depth. 

The Mariners cannot spend the offseason presenting 2026 as a strange collection of injuries and down years that will naturally correct itself. And the arrival of more prospects doesn’t refund the season they wasted. They knew the standard and they unfortunately failed to get anywhere close to it.

Ownership and the front office now have to treat 2027 with the urgency 2026 should have created. That means adding proven offense, and not the cheap kind. They need to build a bullpen that can survive more than a couple of injuries. It means deciding whether the same leadership can turn a talented collection of players into a consistent baseball team.

Running it back and hoping for a healthier version of the same roster won’t work. They need a real shakeup, and it could start with moving a popular starter.  Gilbert and the rest of the guys are going to be another year older. Another season of contractual control is gone. The Mariners can still contend again, but it won’t make up for 2026. They had the roster and the recent postseason proof. Instead of being the powerhouse to run over the division, they stepped aside.