Mariners to call up RHP George Kirby to reinforce rotation

What’s the MLB equivalent of a WojBomb? A PassanProjectile? PassanPewPewPew? Anyway, we got one:

The Mariners are indeed slumping, Jeff, thanks for noticing. After demoting the struggling Matt Brash to Tacoma this past week, it wasn’t clear who the fifth starter would be, with most people (read: us) assuming the Mariners would go with a bullpen day, probably anchored by Justus Sheffield. But according to Ryan Divish, that isn’t the case, although he does have some handy advice for you:

Hmmm well that’s mysterious. Luckily, this subsequent response is less mysterious:

Subtle! So it looks like Flexen and Kirby will trade spots in the rotation, and we will be saved a Bullpen Day for now. Promoting Kirby is certainly a much higher-ceiling move than relying on Justus Sheffield and the Bullpen Singers, although a riskier one, considering Kirby has barely scraped 100 minor-league innings since being drafted back in 2019, and his workload will have to be managed carefully.

Kirby lost out on the fifth starter job to Brash this spring training after the latter looked dominant while Kirby labored, posting a 7.04 ERA in 7.2 innings of work, although he did record a dazzling 12 strikeouts. In the five games he’s pitched so far at Arkansas, however, Kirby has proved to be too powerful for the Texas League, striking out almost 35% of batters faced while maintaining his minuscule walk rate of 5.4% and holding batters to a batting average below the Mendoza Line. He’s most recently coming off a seven-strikeout performance against Wichita:

While Brash has the wizard pitch of his slider to pair with his high-velocity fastball, Kirby has a more traditional starter’s complement of pitches: fastball, slider, curveball, and changeup. His fastball is plus, regularly registering in the high-90s and touching triple digits, and he’s been able to produce whiffs on it with minor-league batters by just blowing it past them:

The fastball is where Kirby’s preternatural command really plays up, as well, as he can dot it exactly where he wants to on the black:

Kirby came to the organization with a good fastball that only ticked up as he participated in a major-league training regimen (including getting hashtag-yoked at Gas Camp). His other most-used pitch was a sharp slider, which got raves from scouts in his draft year.

He’s also got a tight curveball with some serious drop that can make batters look silly:

A newer addition to Kirby’s repertoire is this changeup that has a ton of late fade, and it’s probably the pitch that’s come the furthest over his time in the organization.

In Arkansas, Kirby has been consistently working just five innings per outing, which is good considering how carefully the Mariners have handled him in the past, but will shift a fair number of innings to the bullpen. Luckily, the rest of the Mariners rotation has been fairly stalwart in the innings-gobbling department, so Kirby might actually be an upgrade over Brash as far as that goes. However, look for the Mariners to be fairly conservative in his usage, especially as he pitched just a hair under 68 innings last season after working only at the alternate site in 2020.

As tantalizing as Kirby’s stuff is, it’s important to manage expectations, both for his workload and how his stuff will play in the big leagues. Logan Gilbert didn’t find immediate overwhelming success in the majors, and likely, Kirby won’t, either. Oftentimes with a deeper arsenal, it takes more time to tweak how it will all work together at the big-league level. For Gilbert, we’ve seen him lean much less heavily on his curveball, which was a whiff-producing machine in the minors, while relying more on his slider and cautiously working in a changeup. Fooling Double-A hitters is one thing, and facing literally the best hitters in the world is quite another. However, in a year that already feels like it’s becoming less about pushing for a playoff spot and more about Letting the Kids Play, Kirby has earned his spot on the playground.