Diamondbacks pitching prospect Kyle Amendt opens up on developing his fastball and curveball and competing in the Arizona Fall League.
Kyle Amendt is one of the rising arms through the Diamondbacks system, quickly getting up to Triple-A Reno in his first full season in the organization. After his strong year, the team sent him out to the Arizona Fall League to get him more reps and evaluate him as a potential call-up candidate for the 2025 season.
Amendt doesn’t have a high-velocity fastball, sitting in the low 90s, but it features a vertical shape and gets a lot of induced vertical break. In Reno, he averaged 90.8 MPH on 165 4-seamers, but it induced an average of 17.1 inches of vertical break while only getting 0.3 inches of arm-side run. It’s worth noting that most of the parks in the Pacific Coast League are higher elevation, which affects the movement.
Because of the shape and movement, along with his ability to hide the baseball behind his massive 6’5” frame, it is a very effective swing-and-miss offering at the top bar of the strike zone. It’s a pitch he has a lot of confidence in when he’s trying to miss bats.
“It’s my best against your best,” said Amendt. “I’m going to throw it there and let you hit it. I’m not very weary about not throwing it in the zone and letting the hitters hit it.”
The vertical fastball shape came as a result of changing his arm slot to develop his curveball. Coming out of high school, he walked on at Southeastern Community College. At the time, he was pretty much a fastball-only pitcher throwing out of a high three-quarters arm slot with a loopy, bad curveball. Faced with a situation where he wasn’t going to get innings without developing a useful offspeed pitch, he drew inspiration from a couple All-Star pitchers famous for featuring that pitch.
“I watched Adam Wainright with the Cardinals all the time. I just went and started watching his curveball. He’s got a big one, it’s fun to look at, fun to watch, so I watched that quite a bit. Then I went and started watching Clayton Kershaw’s curveball, he’s got a funky one too. If I’m going to try to make a new pitch, I might as well have some fun trying to learn it.”
Looking to try to get a 12-to-6 shape to get the right amount of depth on the curveball, he raised his arm slot to where it is today. Based on his movement numbers in Triple-A, Amendt’s curveball has adopted that shape with 51 inches of drop and 1.4 inches of arm-side break. As he got his curveball into shape, the fastball naturally followed.
Following his successful stint at Southeastern, Amendt transferred to Dallas Baptist ahead of his redshirt junior season. He broke out in the 2023 season, pitching to a 1.75 ERA and a strikeout rate of 45% before getting selected in the 9th round of the 2023 MLB Draft by the Diamondbacks. In that draft, they also selected two of his teammates from Dallas Baptist.
Amendt quickly raised through the ranks, climbing up to Double-A Amarillo in June after 11 dominant relief outings as the primary closer in Hillsboro. He then pitched to a 2.89 ERA in 19 appearances with Amarillo before the aggressive promotion to Triple-A in August.
Climbing up the system quickly can be its own challenge. Each level has its own pitching coach, although the development is streamlined throughout the organization. Each coach reports to Minor League Pitching Coordinator Kyle Driscoll.
It’s worth noting that Amarillo and Reno play completely different compared to Hillsboro. The thin air and swirling winds causes batted balls to carry more. Amendt also believes the quality of batters he faces plays the biggest role in the increased difficulty.
“Honestly, I’d say the biggest change moving up the level isn’t really tied to sea level, it’s just hitters. They’re better hitters, especially when you get to Triple-A. You have guys coming back doing rehab stints and you have guys who have a substantial amount of big league time. They know the zone well and they’re good hitters. I don’t like to add in oh I’m playing at 5,000-ft elevation, my stuff is not as good. They still got to hit, you still got to pitch.”
Following the season, Amendt was sent to the Arizona Fall League. It was a chance to get re-acquainted with his former teammates in the organization and fellow 2023 draftees.
“It’s been awesome. Meeting a whole bunch of new guys, moving back to Arizona is kind of nice too, I do enjoy it down here. Being able to play with some of the guys I got drafted with too, like Tommy [Troy], Gino [Groover], Phil [Abner], and playing with Dylan Ray and Yu-Min Lin is fun too. I played with D-Ray and Lin quite a bit when I was in Amarillo. It’s good to see them again and play with them.”
Amendt described the level of hitters in the fall league as good, calling it a great league.
“All these guys are prospects, orgs think very highly of them to send them here. It’s been really good competition. I’m seeing a lot of faces that I saw on T.V. when they got drafted. It’s also fun to be able to play against them.”
Amendt is looking to get his innings in and get ready for next season. His season started a little late, as he spent the first 18 days of the minor league season on the injured list. The fall league will be an opportunity to make up for those lost reps. He’s looking to get back to commanding the zone more like he did with Hillsboro and Amarillo, as his walk rate spiked to over 20% when he got to Reno.
So far in two outings in the fall, he’s allowed an unearned run in 2 1⁄3 innings, with four strikeouts and just one walk. Continuing to pitch well in the fall could earn him an opportunity to showcase himself in big league Spring Training next season and put himself on the map for a potential early-season call-up.