Geoff Hartlieb has never had any success at the Major League level, and yet the Yankees decided the 31-year-old with a career 7.37 ERA was worth a MiLB deal with an invite to Spring Training. It wasn’t a late-winter signing either, the Yankees acquired him during Game 2 of the 2024 World Series, scooping him up before other teams were really looking hard into acquiring his services.
He’s rolled into Spring Training with the Yankees with a new approach though; the normally fastball-heavy right-hander has some newfound confidence in his nasty slider, a pitch that’s become his go-to weapon now. The Yankees have had success with their NRI pool under Matt Blake, finding hidden gems such as Ian Hamilton in recent years. With the Yankees having open spots in their bullpen, could the hard-throwing veteran finally find his MLB footing in the Bronx?
Why Geoff Hartlieb Could be the Yankees’ 2025 Underdog Story
The Yankees have continued to show why they’re one of the most highly-revered teams in MLB when it comes to pitching development, as there’s a slew of arms that have taken serious improvements in pitch quality. With how many arms have either improved their repertoires or added a new pitch, Geoff Hartlieb’s improvements have flown under the radar early-on in Spring Training.
When the Yankees acquired him in free agency, the right-hander came off of a tough season where he had some decent numbers in Triple-A but struggled to do much of anything at the Major League level once again. His slider and cutter became more prominent weapons in his arsenal while in Triple-A, but neither pitch got enough shine in the big leagues, as he pitched for an organization in Colorado that isn’t exactly known for it’s pitching development prowess.
Early in Spring Training the Yankees and Geoff Hartlieb have made a loud change in his approach on the mound; throw your best pitch as often as possible. His slider is a nasty weapon that picks up a lot of whiffs and soft contact, and the Yankees have had the right-hander throw the pitch 56% of the time, which is nearly 20% up from his Triple-A usage rate (37.1%), and this pitch has ripped through opposing batters.
They’re whiffing 47.1% of the time against his slider while recording zero hits against the pitch, as Geoff Hartlieb has struck out half the batters he’s faced through his first three Spring appearances. With a career 19.9% K%, a sudden improvement in his swing-and-miss abilities could make him an enticing reliever to follow this season.
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His slider was such a good pitch that the Yankees didn’t make many alterations to it, they’ve just had Geoff Hartlieb throw that pitch far more often than he had before. Few organizations are better with sliders than the Sam Briend-Matt Blake led Yankees have been over the past five seasons, sporting the best slider Stuff+ (115) in baseball since those two took over in 2020.
What the Yankees have changed with Geoff Hartlieb are his fastball shapes, some of which isn’t entirely on the organization as the effects of Coors Field neutralized the vertical ride on his four-seamer and cutter. Both pitches have gained over 3 inches of vertical ride, which allow them to tunnel well off of his slider since neither pitch has much lateral movement and they can steal strikes at the top of the zone to set up a nasty breaking ball in the dirt for a strikeout.
Early in Spring Training Geoff Hartlieb’s fastball velocities have been down, but yesterday he looked as good as ever, sitting 95.8 MPH on the four-seamer and reaching 96.2 MPH with it. If his four-seamer sits at 95-96 MPH, that pitch will be a very successful weapon to pair with his slider, but since Hartlieb has also thrown a sinker, the Yankees obviously went to work to ensure that it can be more effective in 2025.
The sinker he throws has lost three inches of drop, but has gained three inches of lateral movement, which is a good trade-off considering that Hartlieb already has a pitch that can deceive hitters down in the zone. Now his sinker can steal strikes by peppering the first-base side of the plate or it can jam right-handed hitters on the inner-half of the plate, and it gives each pitch in his repertoire a distinct role.
As his velocity creeps back up, I expect the pitch quality scores to improve as well, and the Yankees could have a pitcher with a vicious slider who can also throw three distinct fastballs in any given count. Throw away the back of his baseball card; the Yankees look above and beyond a pitcher’s career ERA, and if these early-Spring changes stick, Geoff Hartlieb could be another weapon for a Yankees’ bullpen with some serious firepower.