Pittsburgh Pirates Prospects: Building A Rotation Of Underrated Pitching Prospects

Building a potential future starting rotation for the Pittsburgh Pirates consisting of lesser talked about prospects

You could make a future rotation of Pittsburgh Pirates pitching prospects. A starting five of Paul Skenes, Bubba Chandler, Jared Jones, Anthony Solometo, and Thomas Harrington looks pretty good on paper. If the Pirates were to open the year with that as their rotation, that’s honestly better than some Major League rotations. There are plenty of other potential future rotation options behind them.

But that’s a rotation of top-pitching prospects. Skenes, Jones, and Solomon were all part of at least one top 100 prospect list. Chandler’s outstanding second half should put him on some top-100 prospect lists going into 2023. Harrington showed off some good stuff, as well. These five are on most prospect radars.

What I want to build is a rotation consisting of underrated Pirates pitching prospects. Most of these prospects aren’t on any top Pirates prospect list. But they are still prospects who deserve some recognition.

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.

Khristian Curtis

Khristian Curtis was a 12th-round pick by the Pirates in 2023. But Curtis was ranked as a much better talent than a 12th-round pick. MLB Pipeline had him as the 197th-best prospect in the draft. Baseball America was significantly more bullish on him, placing him at 146. Meanwhile, Future Star Series puts him directly in the middle at 172.

Curtis’ 2023 season was not great. In 64 innings, Curtis pitched to just a 7.03 ERA, 1.73 WHIP, and 1.66 K:BB ratio. The right-hander had an 18.7% strikeout rate along with a mediocre 11.2% walk rate. His 1.69 HR/9 rate was also below average in the PAC-12. Curtis did, however, look significantly better in 2022, but only pitched 22 innings.

There were significant injury concerns going into the draft, which led to him falling so far. He did not pitch in 2021 due to ulnar nerve surgery. Elbow issues lingered into 2022 as he needed another procedure to remove stitches in his arm. Although most sites had him ranked as a top 200 draft pick, he ended up going 347th overall, but the Pirates signed him to an overslot deal worth nearly $500K.

When healthy, Curtis can run his fastball into the low-mid-90s with movement. His slider is his best breaking pitch. Scouts observed it as a very firm offering that comes in the upper-80s. Because of how hard he throws it, some say it has cutter-like attributes. Curtis’ best off-speed pitch is his fading change-up. It’s probably the best pitch of his arsenal. He’ll also throw a looping curveball, but it’s considered the worst pitch of his arsenal.

Curtis keeps his arm relatively short throughout his delivery. He mostly uses his size to generate velocity, as he does not throw with an overly complicated or high-effort delivery. His arm slot is from a high three-quarters angle as well.

Curtis has a lot of physicality on his side as he stands at 6’5”, 210 pounds. It will be interesting to see how Curtis can pitch in a fully healthy season. MLB Pipeline made it sound like he had trouble tunneling and commanding his pitches because of his injuries. Future Star Series stated that he is trending upward.

Hung-Leng Chang

Hung-Leng Chang made a good first impression in 2022 and got off to a decent start in 2023 at the Florida Complex League. But things went south once he got sent to Bradenton. Still, Chang is one of the more interesting pitching prospects in the lower levels of the Pirates’ system, and I wouldn’t be shocked if this was just a small sample size fluke.

Chang pitched 25.1 innings at the FCL prior to his promotion. He owned a 3.20 ERA, 3.53 FIP, and 1.22 WHIP throughout those innings. While Chang struck out a respectable number of batters with a 23.6% strikeout rate, his 11.3% walk rate was a tad high and about 3% worse than during his 2022 sample size. But Chang carried a 46.2% ground ball rate and didn’t allow a home run.

Chang pitched the same amount of innings at Bradenton as he did at the FCL, but the numbers were significantly worse. The young right-hander had a 7.46 ERA, 8.30 FIP, and 1.82 WHIP. Chang only struck out 14 batters while walking a dozen. But more worrisome was the amount of home runs he gave up. Chang allowed seven dingers, leading to a 2.49 HR/9 rate. Granted, with a 23.3% HR/FB ratio, one could make the assumption that he could regress to the norm next season. On the plus side, Chang did reel of ten innings, only allowing three earned runs, one home run, two walks, and seven strikeouts through his final three starts.

Chang uses a wide variety of pitches on the mound. His sinker sits in the low 90s and tops out around 95 MPH when he starts games. He typically sits around 2250-2300 RPM with this pitch. Chang’s slider is his primary breaking ball, an offering that sits in the low 80s with around 2050 RPM. There is a bevy of other offerings Chang throws in as well, including a cutter (mid-80s), curveball (upper-70s), and changeup (low-80s).

Chang throws from a three-quarters arm slot and has been described as an athletic pitch. His motion on the mound is fluid, and he can throw all his pitches for strikes. There is a lot of physical projection with Chang. He is 6’3”, 160 pounds, giving him a slender frame. At 22, Chang could start the year at Greensboro despite barely pitching at Bradenton.

Antwone Kelly

Antwone Kelly was one of the Pirates’ international signees in the 2020-2021 off-season. So far, Kelly has had a solid professional baseball career, but he finally reached Bradenton last season. But overall, he pitched well between the Florida Complex League and A-Ball, tossing a total of 43.2 innings.

Between these innings, Kelly owned a 2.89 ERA, 2.95 FIP, and 1.26 WHIP. Kelly’s 9.9% walk rate may not have been great, but he offset that with a strikeout rate of nearly 30% (29.1%). Impressively, he did not allow a single home run. But he didn’t have an elite ground ball rate, only clocking in at 35.5%.

Kelly appeared in two games for the Marauders at the end of the minor league season, but this gives us some insight into his pitch mix. Kelly primarily threw a low-80s slider in these games, with a low-90s four-seam fastball as his second most used pitch. His sinker was his third pitch and sat with similar velocity to his four-seam fastball. He occasionally mixed in a change-up, but it was rarely used.

Kelly’s delivery is low-effort while tossing from a low arm slot. Kelly starts from the first base side of the mound before firing toward home plate. Kelly stands at 5’10”, 185-LBS. Although he may not be tall for a pitcher, he could add some muscle as he moves up to the minor leagues and, hopefully, the big leagues.

Kelly has worked as both a long reliever and starting pitcher. Last year, he only made two starts, but nine of his 14 total appearances lasted at least three innings. I don’t see a reason for Bradenton to use him primarily as a starting pitcher next season. Kelly is still pretty young, as he doesn’t turn 21 until the first of September.