George Kirby is one of the best young pitchers in the game today. After netting some Rookie of the Year votes in 2022, he continued to show improvement and increased his ERA+ slightly from 109 to 115. More importantly, he leads all of MLB in BB/9 and SO/W with figures of 0.9 and 8.94 respectively. In other words, Kirby doesn't really hand out free passes to first. He's also been able to improve several of his other key statistics, even with a workload increase of roughly 50 innings.
Currently occupying the second spot in the rotation behind ace Luis Castillo, Kirby will take the mound in one of two situations. If he's following a Mariners win, he'll have the ability to close out a three-game Wild Card series or return to Seattle with a dominant 2-0 lead in a longer Division or Championship series. If he's following a Mariners loss, he'll have the unenviable task of stopping downward momentum before it gets out of hand.
The Mariners rotation is young and doesn't have a ton of postseason innings. Rookies Bryce Miller and Bryan Woo obviously have none and Logan Gilbert has just five, making George Kirby the second most experienced starter with his whopping eight innings pitched. Remarkably, his postseason ERA still sits at 0.00, meaning he's clearly able to pitch under pressure, going seven spectacular scoreless innings in an 18-inning slog against the eventual World Series winning Houston Astros. If he's able to keep up the good work he's put in thus far, Seattle might have the most fearsome 1-2 pitching punch on this side of the playoff bracket.
Munoz has done well as the team's new closer but hasn't been without his weaknesses. His ERA of 2.76 is respectable but his WHIP of 1.27 is more concerning. Sure he's giving up slightly more hits than he did last year (7.3 H/9 in 2023 vs. 6.0 H/9 in 2022) but his lack of control is what has been hurting him the most. His BB/9 has doubled from 2.1 to 4.1 and is a big reason why it feels like he's always pitching with the tying runner in scoring position.
The Mariners have the fourth best bullpen in MLB based on ERA (3.53) but being able to finish the ninth inning will be crucial, especially against the other highly competitive teams in the playoffs. It doesn't help that Munoz gave up three earned runs in as many innings in last year's ALDS, speaking to another potential problem pitching in even higher leverage situations. We all know that Munoz has the talent and potential to be one of the best arms in baseball and he won AL Reliever of the Month in August for reason. If he's able to carry his abilities into the postseason, the Mariners will be an even more menacing pitching threat.
It goes without saying that Julio is the lifeblood of Seattle. As the current face of the franchise and the team's best player, it makes sense that his early season slump and subsequent renaissance coincided with the team's own performance, hugging the bottom of the AL West before rising all the way to the top.
He's done it all in the second half - hit for average, hit for power, steal bases, play spectacular defense, all with his signature smile. His post-ASB OPS of 1.001 helped boost the productivity of the rest of the team from a .703 OPS pre-ASB (23rd in MLB) to a .787 OPS post-ASB (7th in MLB). Seattle's offense begins and ends with Julio and despite being just 22 years old, he's clearly been a key leadership figure in the clubhouse.
With Jarred Kelenic returning from the IL to continue his breakout season, Cal Raleigh's abilities on both sides of the dish, J.P. Crawford's reinvention, and Dylan Moore's surprising productivity, Seattle seems to be riding the highs of a competitive division race and push for October baseball. With this there pieces, this level of hype, and some timely hitting, the sky is the limit for this young and exciting. Mariners team.