How Seattle Mariners Ace Points the Way to Future Success for Hot Twins Rookie

[Cody Christie]

For the fastest-rising pitching prospect in baseball this year, the early big-league returns have been mixed--but not discouraging. One more famous starter from an AL rival might be the perfect comp for what the Twins still hope their young hurler will become.

Image courtesy of Brad Rempel-USA TODAY Sports

The Twins have seen plenty of pitchers raise their prospect stock this season, but the name that's turned the most heads is Zebby Matthews. As fans and analysts look toward the future, it's hard not to draw parallels between Matthews and some of the premier young pitchers in the majors today. One such comparison that stands out is with George Kirby of the Seattle Mariners, a young ace who's quickly built a reputation for his exceptional command of the strike zone. How does Matthews stack up against Kirby, particularly in the areas of command and control? Let’s dive in.

The Seattle Mariners selected Kirby with the 20th overall pick in the 2019 MLB Draft. He has established himself as one of the best young pitchers in baseball, thanks mainly to his impeccable control. Known for pounding the strike zone, Kirby made waves in 2023 by leading baseball with a 0.9 BB/9 and a 9.1 strikeout-to-walk ratio. His ability to command all his pitches, particularly a fastball that sits comfortably in the mid-90s, has helped him become one of baseball's best young starters.

Kirby’s approach is straightforward, yet effective: challenge hitters in the zone and trust his stuff to generate weak contact. This aggressive mentality is backed by his stellar mechanics, allowing him to repeat his delivery consistently and avoid free passes. His walk rate has increased to 1.2 BB/9 in 2024, but he’s also seen his strikeout rate increase from 8.1 K/9 to 8.6 K/9. His Whiff% has increased on his four-seamer, slider, and knuckle curve. He’s using his fastball nearly 6% less often than last season, which is likely one of the reasons for his slight uptick in walks. 

Matthews skyrocketed through the Twins organization this season. Drafted in the 8th round of the 2022 MLB Draft, Matthews might not have the same draft pedigree as Kirby, but he has quickly demonstrated an advanced feel for pitching. In 2023, Matthews posted a 1.3 BB/9 at Low- and High-A, showing that, like Kirby, he understands the value of putting the ball in the strike zone. In 2024, Matthews posted unheard-of walk totals on the way to making his big-league debut. Across three levels, he walked just seven batters in 97 minor-league innings. He did this while also increasing his strikeout rate from 9.6 K/9 in 2023 to 10.6 K/9 in 2024. 

Matthews and Kirby are also similar in the variety of their pitch mix. Kirby has utilized five pitches regularly this season, and Matthews has relied on a similar number of pitches in his repertoire. They both have a fastball in the mid-90s and use a slider regularly as a secondary pitch. Both have shown the ability to throw strikes consistently, an attribute that bodes well for their longevity and success at the highest level.

Matthews obviously has a long way to go before he will be mentioned in the same conversations as Kirby. While Kirby is already a mainstay in Seattle’s rotation, Matthews is still at the beginning of his big-league career. However, the similarities in their command profiles suggest Matthews has the potential to carve out a successful career by attacking the zone and limiting free passes. Matthews is off to an encouraging start for the Twins, and the organization can hope that he can reach a similar ceiling to Kirby.

Ultimately, both Kirby and Matthews showcase the importance of command and control in modern pitching. As the Twins look at their future rotation, keeping an eye on Matthews's development--and comparing it to the success Kirby has found--could provide a blueprint for harnessing command-oriented pitching talent. If Matthews can continue to refine his command and maintain his low walk rates, the Twins may have a future big-league standout.

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Can Matthews follow a development path similar to Kirby's? How does Matthews need to improve over the next year? Leave a comment and start the discussion. 

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[purplesoldier4u]

Zebby's last game was tough. Sometimes, and it's very early in his MLB career, it's good to get that eye-opening game to use as motivation.

[Blyleven2011]

It's a BIG IF  at this time ...

One can only dream of an ace as good as kirby  ...

[Doctor Wu]

Very good article, along with plenty of stats to support your argument. It would certainly be very satisfying if Zebby can develop and be as good a pitcher as Kirby. I won't bet against it happening. 

[LambchoP]

Zebby is one of our most intriguing arms coming up. However, he should never have had to make his debut this year. He only had a handful of starts in AA, but he did pitch well. He only got what, 3 AAA starts and he got hit around a bit. If we had legit major league depth and didn't need to rush our young guys because of injuries, Zebby should have finished the year in St Paul and then started there next year. Relying on rookies for 3/5ths of a potential playoff rotation is super risky. I think SWR and Festa have both earned a rotation spot next year. Zebby and Morris could use a bit more seasoning. If we sign a decent starter on a one or two year deal to stick in the rotation, I like our depth in AAA. Of course as we've found out the hard way, you can NEVER have too much pitching!