Potanko: Sean Sullivan’s Improvement Subtle, But Significant

ALTOONA- One of the final conversations I had during my latest trip to Altoona involved promising young pitcher Sean Sullivan.

The Pittsburgh Pirates drafted Sullivan in the eighth round in 2021 out of the University of California, Berkeley. During his three years in college, Sullivan posted a 6-7 record, with an ERA of 4.09 in 110.0 innings pitched. 

The slot value for Sullivan’s pick was $192,900, and he signed slightly under slot at $175,000.

Sullivan struggled in his first year in High-A Greensboro, which isn’t shocking. The South Atlantic League can be brutal for some pitchers, but there were some positive signs. 

Away from First National Bank Field, Sullivan posted an ERA of 3.38 compared to a 5.52 at home.

The righty started the 2023 season in Double-A Altoona, and now we’re beginning to see why the Pirates liked him. One of the more significant stats that stood out from 2022 to this year was the HR/FB rate.

In ’22, Sullivan allowed a flyball or home run 26.7% of the time, and now in Altoona, he’s dropped that significantly to 9.0%. 

Other positive signs include an increase in LOB% to 74.6%, BB/9 dropped to 3.02, and HR/9 to 1.25. The numbers don’t pop at first sight, but it’s improving in the right places.

Some of the “improvements” aren’t measured by a metric, or at least not yet. Of course, I’m talking about the game’s mental portion. Sullivan, from my vantage point, has improved immensely in this area.

“One of the things you’ll see from Sean at times is he puts a lot of pressure on himself,” said Curve manager Callix Crabbe. “What I’ve noticed here lately is that weight or pressure is starting to dissipate. The game doesn’t seem to be speeding up when he’s out there, and he’s finishing his pitches.”

Crabbe continued.

“I think when your mind is clear, the other parts of the body, the endpoints, are going to be more stable. He’s been throwing the ball really well. That big extension that quick windup to home plate, really keeps hitters uncomfortable. He doesn’t have a huge fastball, but it definitely plays beyond its years and miles per hour for sure.”

It’s nice to get the manager’s perspective, but it’s even nicer to get the actual player’s thoughts and pick their brain on how they think they’ve matured.

On Aug. 3, before I showed up to Altoona, Sullivan pitched five scoreless innings, gave up just three hits, and walked two. 

“I definitely needed that start,” said Sullivan. “I was in a bit of a rut, but that’s baseball. You just have to learn how to work through it. I feel like even though the results haven’t been there, I’ve been trusting my stuff a lot more.”

Sullivan continued.

“I haven’t changed anything; it’s just the hitters get more experience throughout the year and become tougher in the at-bat. It’s my job to learn how to combat that. When you face a lineup for the third time, they got more stats on you and know what your stuff looks like. You have to learn how to finesse and don’t stray too far from your attack.”

Sullivan also mentioned that at times throughout the year, he fell victim to becoming too predictable but finally started to trust his stuff and learn from his mistakes.

In the past, I’ve discussed Sullivan’s breaking stuff with him but never had the opportunity to discuss his fastball until our most recent conversation.

Sullivan’s fastball is a curious one. Although it doesn’t have top-notch velocity, it sneaks up on hitters a lot of the time. 

“I got a really low approach angle,” said Sullivan. “It allows me to utilize the top of the zone fairly well. The metrics read 14 horizontal and 14 vertical, so it’s like a rising sinker. It works well, especially with the changeup, although the changeup is a touch-and-feel pitch.

“The changeup compliments my fastball really well because it comes out of the same plane and looks pretty similar. I think that’s why my fastball plays so well most of the time. It’s just about placement, knowing where to throw it, and knowing where guys don’t like it.” 

One of Sullivan’s struggles in last season was finishing hitters off. There would be times when he’d get ahead in the count and couldn’t find that put-away pitch.

Fast forward to 2023, and the issue seems to be improving.

“Getting to two strikes is really important,” said Sullivan. “I think, for the most part, I’m pretty good at getting to two strikes. Putting guys away has been a struggle for me, but over the last two years, I’ve learned a lot. You have to pitch to your strengths and not the hitter’s weaknesses, although it is good to know what they like and don’t like.

“When you get to two strikes, you have to be smart and not give them anything they can hit, no matter what pitch it is. Everything is just a matter of focus. It’s really hard to get in a groove where you’re just going, going, going. You may have a momentary lapse in focus and leave one over the dish with two strikes. That’s why major leaguers are major leaguers; they maintain their focus the entire game.”

Since this interview, Sullivan has gone a combined 12.1 innings while giving up 11 hits, four runs, three walks, and struck out ten in two games.