Zebby Matthews and the Next Frontier of Pitching Development

[Jamie Cameron]

We’ll see Zebby Matthews with the big-league team soon. Let’s take stock of his early season performance in AAA and dig in on some of those tangible improvements.

Image courtesy of Dave Nelson-Imagn Images

For many Twins fans, it was perhaps a surprise when David Festa got the call to the Twins rotation over Zebby Matthews. After all, Zebby was lined up to take Pablo’s day in the rotation. Matthews has also made tangible performance gains in 2025. The move made sense, though. Festa is MLB-ready in his own right. He has more experience at Triple-A. His promotion allowed the Twins to build up some extra rest for a rotation that has rounded into form.

We’ll see Zebby Matthews with the big league team soon. Let’s take stock of his early-season performance in the minors and dig in on some of those tangible improvements.

Matthews has made three starts in AAA thus far in 2025, most recently against the Iowa Cubs, probably the best Triple-A lineup in baseball. In those three starts he’s thrown 15 innings and managed a 1.28 FIP, posting a 32.7 K-BB% in the process. That’s dominant.

One inescapable truth, and one that underpinned folks clamoring for Zebby to be promoted to the big leagues to replace Pablo Lopez, is a significant uptick in velocity across the board. In 2024, a year in which Matthews saw three different MiLB levels (and a brief, challenging stint in the majors), his fastball averaged 95.6 mph. Through 15 innings in 2025, he's averaging 97.2 mph, he's touched 99.5 mph, and he’s using it more (45%, up from 37% in 2024).

It’s not just the fastball. The velocity is up across the board.

	vFA	vFC	vSL	vCU	vCH
2024 (MiLB)	95.6 mph	90.8 mph	85.9 mph	80.2 mph	85.4 mph
2025 (MiLB)	97.2 mph	92.9 mph	89 mph	84.8 mph	87.3 mph

To put this in context: 97.2 mph would have been the fastest average fastball for a starter in the majors in 2024, ahead of Dylan Cease (96.9 mph) and Tarik Skubal (96.8 mph). His slider would be the second hardest, on average. While we’ve been astounded by Matthew’s velocity gains in 2025, it still feels like we’re underselling it.

So, what’s the impact of velocity gains? It’s giving him significantly more margin for error with his one remaining area of opportunity, command, (more on that later). The amount of contact opposing hitters are making in the strike zone is way down, from 88.7% in AAA in 2024, to 78.8% in Triple-A this year. His CSW% (called + swinging strike percent) is up from 28.6% in AAA in 2024, to 34.6% in AAA in 2025. These are not small improvements.

If you’re a stuff nerd, that's taken a step forward. Please consult your preferred stuff plus model of choice. This is trending towards becoming one of the better arsenals out there, aided by new found elite velocity.

So, what are the opportunities for Matthews? One aspect of his performance we should continue to pick apart is control versus command. The two are often conflated. He’s elite at one, while the other is a work in progress. 

Considered in its simplest form ‘control’ is the ability to throw strikes, ‘command’ your ability to manipulate those strikes throughout the strike zone. The latter is much more complicated. After all, you have to consider the relative strengths and weaknesses of a particular hitter, the sequencing of your pitches, and so on.

Matthews threw ~70% strikes in his 2024 season. His 1.9 BB% in his MiLB innings would easily be the best in the majors (George Kirby led the league at 3%). Matthews is throwing slightly less strikes in 2025 (68%). I’d contend that’s a net positive. Knowing how, when, and where to leave the strike zone is an important skill in learning to deploy your arsenal, particularly when it features a fastball you can run up to 100 mph. To put it bluntly; how can you make a batter chase if you are never out of the strike zone? 

Let’s address the command directly. Location+ is a count and pitch type adjusted stat that serves as a measure of the pitcher’s ability to put the ball in the right place. While that’s not perfect, it tells an interesting story. In his brief MLB debut in 2024, Matthews had a Location+ of 97. If he was qualified, that would have ranked 52nd out of 58 starting pitchers in the league. Matthews’ Location+ was worst on his fastball and cutter, two pitches that account for ~60% of the pitches he throws. To be direct, he was outstanding at throwing strikes, not yet outstanding at putting those strikes in the right places.

The remaining area of opportunity for Matthews is training command: spotting his pitches where they are called, reducing his miss rate, and ensuring misses don’t leak over the heart of the plate. This is where his velocity creates increased margin for error, but command metrics are the aspect of Matthews’ performance I’ll be paying closest attention to when he gets the call.

One final aspect of development we should mention is a pitch tweak. Matthews adjusted his changeup this offseason. Primarily for use against left handed hitters, he’s worked on executing it over the plate to ensure they can’t sit on a cut fastball or breaking pitch inside. You can see an example below of how these were executed against Owen Caissie after getting to 0-2 against him in his most recent start (both changeups in this at-bat were swinging strikes).

Matthews is more equipped to handle MLB hitters in a second stint with the Twins, whenever that may come. It’s now elite velocity, elite strike throwing, and a diverse arsenal that should beget success at the highest level. If he can continue to improve his command, he has a chance to be a playoff caliber starting pitcher.

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[Karbo]

Maybe the Yankees would be a good trade partner for one of our starters, preferably SWR or Paddack, I have no idea what the Twins could get or even if they have anyone they would want, but NY need starters.

[HerbieFan]

As the losses and injuries mount....how long til we hear the "Trade Pablo" speculation?  Org has done a good job developing pitching.  Now, about the lack of hitting....:)

[Mahoning]

Three dominant starts for a total of 15 innings. That tells me plenty about the Twins' approach to pitcher "development," which is, training them to have no ambition to go deep into games. That and "building up rest." What can that possibly mean? No one gets stronger by resting. I swear, if the Twins had a young pitcher who wanted to be, say, the next Roger Clemens, they'd be horrified and he'd never be allowed to develop into a bulldog. But they'd sure build up his rest. 

[Doc Lenz]

Trying to remember if Don Drysdale or Nolan Ryan were worried about control and command.

[DJL44]

Option SWR until they can find a trade partner for Paddack. SWR doesn't deserve it but Zebby should be in the majors.

[twinstalker]

Zebby is fantastic, but two points I've made before:

1.  Zebby wasn't lined up to take Pablo Lopez' start.  It would have been after four days rest, and he was working on 5-6 days rest right then.  He pitched on a Tuesday, and Pablo's start was to be Sunday, four days rest.  It was too rushed for him to get all that many innings.  Starting Festa on his regular day and moving part of the rotation back was the smart, necessary move.

2.  I think the Twins will do everything they can to keep Zebby under 124 days of service time, which means if they keep him down through very early June, he'll wind up with less than 172 days through two season.  That will give them this year and six more prior to free agency.  While that's tough on Zebby, arbitration will still be the same offseason, and his salary will rise to nearly what he'd get in his first free agent year in the end.  Except the Twins will have control for that year.

Bonus point:  Zebby is awesome!

[thelanges5]

Definitely a good problem to have. No such thing as too much pitching depth. Pablo schedule for a rehab start w/Saints Sat I believe. Zebulon and Festavus will be ready for their next opportunity. 

[Blyleven2011]

If zebby continues to improves as a starting pitcher , he could be a playoff starting pitcher ...

First we have to win win and win to  get to the playoffs ...

[bean5302]

I don't see a big change in Stuff+ vs. last year despite the velo increase. Zebby's pitches all grade out at 45-55 (average MLB caliber). No plus offerings (120+).

Matthews should be a solid starter at the MLB level, but he'll probably need better movement to become an upper rotation threat.

[DocBauer]

Tremendous article Jamie!

1] Festa is ALSO a very good young SP. And he was the right choice to come up first...for all the reasons stated...and he's looked really good. He gets better command of his 2 seamer, as well as additional experience, the Twins basically have TWO very good, young starts with some very good upside.

2] Matthews is looking great, but he wasn't quite as good in his 3rd start. And that's OK. Its a process. Nothing wrong with him having a little more time at AAA to work on control and command, as well as his adjusted changeup. Absolutely agree that as good as his control is, you absolutely have to have the command to hit the edges and occasionally throw outside the zone to induce chasing from the batter.

3] As good as Matthews is looking, it's very seldom any pitcher comes up and doesn't have some learning to do. It's called experience. With Lopez back soon, Ryan and Ober rounding in to form, SWR solid and Paddack coming off his best start of the season, no need to rush anyone.

4] It's pretty typical for pitchers to have some sort of pitch limit this early in the season. They are building up their arms, and other pitchers also need work. The idea of a MILB arm throwing 90 pitches and 7 innings this early in the season is pretty rare.

5] Slightly off track, while Morris had a rough 3rd start, I'm super encouraged by his progress and potential. Matthew's great 2024 overshadowed the really good '24 that Morris had. It's entirely possible the Twins have THREE really good, ready made, young starters and not room for all of them to begin 2025. That's a GOOD problem to have.

6] I have a lot of faith in Lewis being a solid ML SP, though he's a little behind the others touched on. With all due respect to Dobnak and possible pen/length contributions yet this season, I believe Lewis should be starting for St Paul and let Dobnak be the the piggyback arm. IMO, that serves both pitchers better going forward.

[LambchoP]

I think the last thing Zebby and all our young starters need to work on is being efficient and getting deeper into games. We've seen what happens this year when our MLB starters only go 4-5 innings. We have to rely on way too many pen arms and eventually one of them blows the game. Zebby and Festa will be in the rotation for the second half is my guess.

[DJL44]

2 hours ago, LambchoP said:

I think the last thing Zebby and all our young starters need to work on is being efficient and getting deeper into games. We've seen what happens this year when our MLB starters only go 4-5 innings. We have to rely on way too many pen arms and eventually one of them blows the game. Zebby and Festa will be in the rotation for the second half is my guess.

If you want him going deeper into games, he's going to have to drop back on the velocity.

[bean5302]

1 hour ago, DJL44 said:

If you want him going deeper into games, he's going to have to drop back on the velocity.

Hope that's not the case, but I fear you're right. If he's wearing out at 70 pitches now, he'll be a totally dead arm by August.

[twinstalker]

18 hours ago, bean5302 said:

I don't see a big change in Stuff+ vs. last year despite the velo increase. Zebby's pitches all grade out at 45-55 (average MLB caliber). No plus offerings (120+).

Matthews should be a solid starter at the MLB level, but he'll probably need better movement to become an upper rotation threat.

As big a fan as I am, I agree with this.

[twinstalker]

1 hour ago, bean5302 said:

Hope that's not the case, but I fear you're right. If he's wearing out at 70 pitches now, he'll be a totally dead arm by August.

I understand this sentiment, and you're right based on the premise you lay out.  But is he wearing out?  Two things:  first, the Twins are likely limiting the number of pitches, and there might be some third time through order issues (rather than being taxed) if he's getting hit later, I haven't looked.  Second, low pitch counts for minor leaguers are common, especially early.  70 pitches isn't as much the result of being tired, it's just the process of getting to 100 pitches by August.  Maybe that's all one thing, not two!

[twinstalker]

16 hours ago, DocBauer said:

5] Slightly off track, while Morris had a rough 3rd start, I'm super encouraged by his progress and potential. Matthew's great 2024 overshadowed the really good '24 that Morris had. It's entirely possible the Twins have THREE really good, ready made, young starters and not room for all of them to begin 2025. That's a GOOD problem to have.

6] I have a lot of faith in Lewis being a solid ML SP, though he's a little behind the others touched on. With all due respect to Dobnak and possible pen/length contributions yet this season, I believe Lewis should be starting for St Paul and let Dobnak be the the piggyback arm. IMO, that serves both pitchers better going forward.

That game this past week stressed me out like no other.  Morris and Lewis are favorites of mine.  Morris is my favorite Twins prospect (not saying best), and I actually met Lewis a year ago when he was in town for the Diamond Awards (minor league pitcher of year).  I think Lewis' 2024 is one of the most misleading statlines due to rustiness after missing time with the shoulder.  After early walk issues, he was dominant.

Morris is 15 months younger than Zebby.  That doesn't matter as much with pitchers, and they're both around 24, not 19, but in terms of Twins development, I do think it's a thing.  Zebby did not have Morris' 2024 back in 2023.  Admittedly, they were drafted the same year and seem to have taken the same path from there, with Zebby jumping ahead, so I'm not sure the age difference means anything in this case.

[bean5302]

2 hours ago, twinstalker said:

I understand this sentiment, and you're right based on the premise you lay out.  But is he wearing out?  Two things:  first, the Twins are likely limiting the number of pitches, and there might be some third time through order issues (rather than being taxed) if he's getting hit later, I haven't looked.  Second, low pitch counts for minor leaguers are common, especially early.  70 pitches isn't as much the result of being tired, it's just the process of getting to 100 pitches by August.  Maybe that's all one thing, not two!

It's possible the Twins are foolishly limiting pitch count. It's my very strong opinion that routine prevents injury and Baldelli, in particular, seems to randomly decide to pull a guy after 70 pitches or let them go to 100 pitches on the next start. I don't know what the overall front office perspective is, but guys in the minors who you expect to be in MLB during the season shouldn't be seeing a workload spike of 40-50% when they get to the big show IMHO.

Baldelli has a long history of wearing a bullpen out to the point of near exhaustion by August only to watch everything collapse. I don't like the look.

[Jamie Cameron]

On 4/19/2025 at 6:55 PM, bean5302 said:

I don't see a big change in Stuff+ vs. last year despite the velo increase. Zebby's pitches all grade out at 45-55 (average MLB caliber). No plus offerings (120+).

Matthews should be a solid starter at the MLB level, but he'll probably need better movement to become an upper rotation threat.

There's been a huge uptick in Stuff+ from last year.

Hit MLB debut Stuff+ was 99 (TJ Stats), this season has been 109-111. Fastball has gone from around 100 to 115-117. All of his pitches have improved. Only his cutter is around average per Stuff+, depending on what model you're using.

[bean5302]

11 minutes ago, Jamie Cameron said:

There's been a huge uptick in Stuff+ from last year.

Hit MLB debut Stuff+ was 99 (TJ Stats), this season has been 109-111. Fastball has gone from around 100 to 115-117. All of his pitches have improved. Only his cutter is around average per Stuff+, depending on what model you're using.

This is about how I have Stuff+
35 = 70-79
40 = 80-89 = (Cutter 89, Changeup 89)
45 = 90-99 = (Fastball 97), Cutter 97 (40 -> 45)
50 = 100-109 = (Slider 105, Curve 105), Changeup 105 (40 -> 50), Curve 105 (stayed 50)
55 = 110-119 = Fastball 111 (45 -> 55), Slider 113 (50 -> 55)
---------------------------------------------------------------------------
Plus pitches
60 = 120-129 = 
65 = 130-139 = 
70 = 140-149 = 
75 = 150-159 = 
80 = 160+
So Zebby's stuff plus has gone up, but he still doesn't have a single "plus" pitch. IMHO, going from a borderline 45 grade pitch to a 50 grade pitch or a borderline 50 grade pitch to a 55 grade isn't some huge leap. He's better, and that's great, but he hasn't improved like Jax did from the rotation to the 'pen or something.

[DJL44]

Zebby has always had good location and the ability to throw strikes. If he's improved his stuff while maintaining his location and ability to throw strikes that is a very good thing.

[Jamie Cameron]

1 hour ago, bean5302 said:

This is about how I have Stuff+
35 = 70-79
40 = 80-89 = (Cutter 89, Changeup 89)
45 = 90-99 = (Fastball 97), Cutter 97 (40 -> 45)
50 = 100-109 = (Slider 105, Curve 105), Changeup 105 (40 -> 50), Curve 105 (stayed 50)
55 = 110-119 = Fastball 111 (45 -> 55), Slider 113 (50 -> 55)
---------------------------------------------------------------------------
Plus pitches
60 = 120-129 = 
65 = 130-139 = 
70 = 140-149 = 
75 = 150-159 = 
80 = 160+
So Zebby's stuff plus has gone up, but he still doesn't have a single "plus" pitch. IMHO, going from a borderline 45 grade pitch to a 50 grade pitch or a borderline 50 grade pitch to a 55 grade isn't some huge leap. He's better, and that's great, but he hasn't improved like Jax did from the rotation to the 'pen or something.

What's your source for stuff+ and the translation of the model you're using to grades for each pitch?

[bean5302]

24 minutes ago, Jamie Cameron said:

What's your source for stuff+ and the translation of the model you're using to grades for each pitch?

My own research and comparisons between the various stuff+ grades pitches got me to break it out as a 10pt for 5pt on a scouting scale.

I was further validated by the very image you reposted by Thomas Nestico image you posted. In the fine print in the image:
 

Quote

"Colour (sic) Coding Compares to League Average By Pitch tjStuff+ calculates the Expected Run Value (xRV) of a pitch regardless of type tjStuff+ is normally distributed, where 100 is the mean and Standard of Deviation is 10 Pitch Grade scales tjStuff+ to a traditional 20-80 Scouting Scale for a given pitch type."

Now, you could argue 50 grade should be 95-104 instead of 100-109, but it's splitting hairs really. It actually makes Zebby's progress look worse:
Old: Fastball (50), Curve (55), Cutter (45), Changeup (45), Slider (55)
New: Fastball (55), Curve (55), Cutter (50), Changeup (50), Slider (55)

[Jamie Cameron]

12 minutes ago, bean5302 said:

My own research and comparisons between the various stuff+ grades pitches got me to break it out as a 10pt for 5pt on a scouting scale.

I was further validated by the very image you reposted by Thomas Nestico image you posted. In the fine print in the image:
 

Now, you could argue 50 grade should be 95-104 instead of 100-109, but it's splitting hairs really. It actually makes Zebby's progress look worse:
Old: Fastball (50), Curve (55), Cutter (45), Changeup (45), Slider (55)
New: Fastball (55), Curve (55), Cutter (50), Changeup (50), Slider (55)

K. I'm all set here. Thanks for reading/commenting. Enjoy your day.