September Woes Cost Seattle Mariners A Playoff Spot

The Seattle Mariners nearly come from behind to grab a playoff spot, but their great second half push ended with a fizzle in September.

The feeling has become all too familiar in the Pacific Northwest.

For the 21st time in 22 years, the Seattle Mariners will not be participants in MLB’s postseason field.

At the conclusion of August, everything was on the upswing for the Mariners with sights of not just a second-consecutive postseason berth in range, but their first AL West title since 2001.

Then September hit.

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An 11-17 month, boldly highlighted by a 4-6 final stretch against the Rangers and Astros, two of the teams they were attempting to chase down, placed the Mariners one game back of the final AL Wild Card Spot to end the year.

Plain and simple, it felt like the ballclub ran out of gas. And it happened in multiple different ways.


The Mariners put themselves in a big hole in the first half of the season, but were able to fully pull themselves out of it with a white-hot August, in which the Mariners went 21-6 and were one of the hottest lineups in baseball over that time.

Fast forward to the final two weeks of the season, and the team couldn’t manage to string together any sort of offense, sans J.P. Crawford. In that time, the Mariners ran out a 93 WRC+ which ranked 19th in the league over that time. What made the pill that much tougher to swallow was the impact bats that were so often relied on didn’t carry their weight.

Julio Rodriguez unfortunately led that charge hitting .113 with a .474 OPS and 28 WRC+ in that time. In the final series against the Rangers he was 1-for-15. 

The superstar center fielder took another step forward in just his age 22 season, so much so that he is set to finish in the top-five of AL MVP voting. But he had his share of struggles in clutch situations over 2023, and over the season’s most important 10 games, he wasn’t himself.

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Teoscar Hernandez followed suit, hitting .176 with a 45 WRC+. Hernandez was streaky throughout 2023. He was phenomenal in both June and August, but was ice cold much of the rest of the year with mounds of strikeouts. His second half of September followed the latter, punching out just shy of 40% of the time.

Cal Raleigh put up a 79 WRC+ in the final two weeks. And Eugenio Suarez posted a 104 WRC+ over the final 10-game stretch.

Those are the Mariners four middle-of-the-order bats. When they collectively are not playing at the level that everyone knows they can, even in a small sample, it is near impossible to find success at the plate. Especially when some of the role players such as Dylan Moore and Jose Caballero were struggling in their own right. 

Crawford couldn’t do it all on his own.

Starting Pitching

The Mariners have thrived off the strength of their starting pitching all season. Much of that has been the emergence of a pair of impressive rookies in Bryce Miller and Bryan Woo.

But all rookies have their valleys in their inaugural season, as those two have. And they hit bumps in the road at the conclusion of the season when the team needed them most.

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In the first of the final two Rangers series in Texas, Miller and Woo both got hit around hard. 

Miller lasted just 4.1 innings while allowing six earned runs in an 8-5 Rangers win. He was off to a better start in his final outing of the year at home against the Astros, a team he had fared well against, through the first three innings.

But a four-spot by Houston in the fourth inning off of long balls from Yordan Alvarez and Mauricio Dubon chased Miller out again early. The Astros went on to win 8-3, in what was arguably the Mariners most pivotal game of the year as a win would have given them a half game lead over the Astros along with having a tiebreaker (so more like 1.5 games).

Woo’s outing in Arlington was even shorter than Miler’s, surrendering six earned runs over 3.1 innings in an eventual 9-8 Rangers victory. His final outing was the strongest of the four between he and Miller as he didn’t allow any runs. The catch is it was over just 3.2 innings where he threw 82 pitches with just 44 being strikes.

Woo threw nearly double the innings in 2023 between Double-A and the majors than he did in the minor leagues throughout 2022. He was asked to do a lot. And truthfully he had probably just about reached his limit.

But the biggest difference-maker was the pair of rough outings from Luis Castillo over his final two starts. The ace of the staff did not show as such against Houston and Texas, allowing five earned runs in six innings against the Astros and a truly disastrous four earned runs and five walks on 86 pitches over 2.2 innings against the Rangers in Game 161, when the Mariners had everything on the line. 

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To be fair, the Mariners offense gave Castillo next to no run support in those contests, tallying two runs over those games. But Seattle needed more from their No. 1 starter in crunch time. They didn’t receive it.

Final Thoughts

Look, in a lot of years 88 wins gets you into the dance. Especially with six teams from each league now being granted postseason bids. In fact, this is the fourth time in the last five full seasons that the Mariners have won 88 games or more. But it has only resulted in one playoff appearance.

That’s the way it goes sometimes. And for the Mariners, despite a little bit of bad luck with the American League being as robust as ever, they had their chances to take a firm grip on their own destiny and control their fate.

But the September swoon really did them in, and painful memories of the final 10 games will linger throughout the offseason. 

With the Wild Card round in full swing, the Mariners are watching from their couch. It isn’t the first time you’ve heard that one.