A Sidespinning Up-Shoot Fastball Has Will Warren Thriving in the Yankees Rotation

Will Warren has come a long way since the New York Yankees selected him in the eighth round of the 2021 draft out of Southeastern Louisiana University. He has also made big strides since he was first featured here at FanGraphs following a 2022 season that saw him reach Double-A. Discovering that his four-seam fastball is a viable weapon is a big reason why. When I interviewed Warren four years ago, his preferred offerings were a sweeper and one-seam sinker.

His numbers in the current campaign are rock solid. Building on a 2025 first full big league season in which he went 9-8 with a 4.44 ERA, the 27-year-old right-hander has toed the rubber 17 times to the tune of a 3.73 ERA and a 3.57 FIP over 89 1/3 innings. Further establishing himself in the Yankees’ starting rotation, he counts seven wins among his 10 decisions.

How and why did Warren go from a hurler who relied heavily on a sinker-sweeper combination to one who aggressively attacks batters with a 93.7-mph four-seamer?

“I always had a four-seam fastball, but it was kind of, ‘He throws from a lower arm slot and doesn’t really backspin the ball all that well,’” the Brandon, Mississippi native explained. “It was kind of, ‘Why would he throw a four?’ But then we kind of dove into, ‘Hey, let’s keep the gyro, let’s have a sidespin, up-shoot fastball.’ I started working on it more and it was missing a lot of barrels, so it became, ‘Alright, this pitch might play a little bit.’ I leaned into it pretty heavy last year, and it has more or less changed my whole arsenal.”

It might be more accurate to say that his usage has changed. Warren’s repertoire, which along with the two fastballs includes a sweeper, a curveball, and a changeup, has remained the same. He simply began embracing a pitch that “looks like it gets perceived cut, because of my arm angle,” rather than believing that it wouldn’t play at the highest level. Abandoning efforts to do what didn’t come naturally was part of the process.

“I was trying to throw 18-inch vertical heaters like everybody else with a good four-seam does,” explained Warren. “I was trying to change my arm angle and get on top of the ball, attempting to climb and get more vert. Over time, with the discussions we had, I realized I didn’t need to. Where I throw from works. That light bulb went off in my head. I started trusting it a little more and throwing it with more conviction. You know how that is. When you throw with full conviction, everything plays up.”

According to Matt Blake, where Warren throws from doesn’t just work, it contributes meaningfully to his effectiveness.

“He’s got a deceptive arm angle,” the Yankees pitching coach told me. “From a low slot, he’s got a four-seam with a little bit of ride to it and a little bit of cut to it. He also does a really good job of getting it to good areas. Since we moved him over to the third base side [prior to this season], it’s a tough angle that you don’t see a lot, with the [four-seam] having some natural kind of flatness to it in the zone. Flatness in a good way.”

To what extent is full conviction in his most-used pitch — paired with the confidence that comes with success — responsible for what is shaping up to be a career season?

“It’s not nearly that simple,” said Warren, whose four-seamer has been thrown at a 39.3% clip and elicited a .206 batting average against and a .374 slug. “This is definitely a tough game. But we have a lot of veteran guys on our staff who have helped me out over the last year and a half. I’ve been learning from them. At the end of the day, it comes down to, you’re really freaking good if you’re playing in the big leagues, so lean on your strengths. You can change some stuff here and there, but keep the main thing the main thing.

“Having more experience under my belt has helped me learn how to pitch up here,” the righty added. “When I first got here… I mean, obviously this isn’t Triple-A anymore. These guys bang around the yard a little bit. Along with believing in yourself and trusting that you belong, gaining information with every pitch and every start is only going to help.”

As we were wrapping up our conversation, which took place in the visiting dugout at Fenway Park, Gerrit Cole strolled by and offered a greeting on his way to the clubhouse. I proceeded to ask Warren what he’s learned from the six-time All-Star and 2023 Cy Young Award winner.

“I’ve learned a lot from Gerrit,” replied Warren. “I’m not going to give away all the secrets, but the main thing is, like I just said, you’re here for a reason. That’s why we’re all here. Gerrit has told me that I’m a really good pitcher. He’s said that whatever makes you Will Warren, go out there and do exactly that. Hitting is hard, so just go out there and pitch.”