Pittsburgh Pirates Prospects: Building A Rotation Of Underrated Pitching Prospects

Sean Sullivan

I’ve covered Sean Sullivan enough to the point where you probably know his name if you have read my stuff. Still, Sullivan isn’t on any top Pirates’ prospect lists, and he’s shown some decent talent over the last two seasons. He spent all of 2023 at Double-A, where he produced some solid numbers.

In 113.2 innings, Sullivan put up a 3.88 ERA, 4.16 FIP, and 1.27 WHIP. The right-hander may have had a sub-par 20.4% strikeout rate, a 5.4% decrease from 2022, but his 8% walk rate and 1.03 HR/9 were both above league average. Sullivan also had a great second half with a 3.55 ERA, 3.53 FIP, and 1.24 WHIP after the All-Star Break. More importantly, however, was that he had a HR/9 of just 0.53.

Sullivan is a guy who relies on command over power. He averages out around 91-94 MPH while throwing a slider, curveball, and change-up. While there’s nothing standout about his pitch selection and every pitch sits at an average level (maybe his slider plays at a 55), he does locate everything well and hits his spots with frequency. The right-hander’s wind-up may look like he throws with a much lower arm slot but brings it back up to a three-quarters slot.

Sullivan is only going to be 23 for the entirety of the 2024 regular season. I think he could be an underrated rotation option for next season. Many are obviously excited to see Skenes, Jones, and Solometo in the majors, but don’t sleep on Sullivan. He’s shown talent at every level of the minor leagues thus far and successfully made the jump from High-A to Double-A.