Rum Bunter's top 10 Pittsburgh Pirates prospects: Where does Konnor Griffin debut?

The Pittsburgh Pirates have been building up their farm system over the last handful of years, and it's started to bear fruit over the past few seasons. They've seen many of their top prospects graduate the farm in the process. This year, the likes of Paul Skenes, Jared Jones, Quinn Priester, Nick Gonzales, and Kyle Nicolas were some of the notable players who entered the year among some of the Pirates' best prospects, and will end it as core pieces of the MLB roster.

Now that the deadline and draft are behind us, the system looks a lot different than it did at the start of the season. That felt like the perfect time to have our staff writers vote on the Pirates' top 10 prospects after a slate of new additions.

But before getting into the list, let's first look at some names that almost made the cut.

Mike Burrows

Mike Burrows is the longest-tenured prospect who'll be discussed here. Drafted in 2018 in the 11th round, Burrows made big steps forward in 2021 and 2022. Many were anticipating what he could do in 2023, but he instead underwent Tommy John surgery in April. Now he's back on the bump, still shaking off the rust. Burrows sits around 93-96 MPH, but has a high-spin fastball and curveball. He'll also mix in a slider and changeup, the latter of which has significantly improved over his last few seasons.

Jack Brannigan

The Pirates took Jack Brannigan in the fourth round of the 2022 draft. Originally drafted as a two-way player, Brannigan has only played the field as a pro. He has mostly played shortstop in 2024, but was drafted as a third baseman and has a handful of games played at second base under his belt. Brannigan is an above-average runner who projects as a plus defensive infielder. He has a strong arm and was able to fire upper-90s fastballs during college. He has the potential to be a 20/20 threat in the future, but his hit tool projects as fringy at best right now.

Yordany De Los Santos

Yordany De Los Santos was one of the Pirates' top international signings in the 2021-2022 offseason. The 19-year-old hit extremely well in the Florida Complex League and recently got promoted to A-Ball with Bradenton. He projects to hit for above-average power and can play shortstop, second base, or third base. He's 6'2", 170 pounds, and already an average runner, so he may have to move to a corner as he matures.

Number 10: Mitch Jebb

The Pirates' 2022 second-round pick, Mitch Jebb, kicks our list off. The middle infield prospect got off to a slow start to his 2024 campaign. His first 205 plate appearances of the season produced a meager .199/.261/.290 triple-slash, paired with a .259 wOBA, and 59 wRC+. Jebb was never expected to hit for much power, but he also was never expected to strike out anywhere near 26.8% of the time. His 7.8% walk rate was also well below his expectations.

But since then, Jebb has been performing as expected. His most recent 190 PAs have seen him bat .307/.439/.425 with a .407 wOBA and 151 wRC+. He has nearly cut his strikeout rate in half to just 13.7% while upping his walk rate to 17.9%. While Jebb still isn't hitting for much power, he's at least gotten his isolated slugging percentage above .100 at .118.

Jebb is meant to get on base via hit or walk. He rarely struck out during college and is starting to show that kind of plate coverage at the professional level. He's also consistently drawn walks at a high rate. Unfortunately, he's not built for power. At best, he'll hit 8-10 home runs. Still, he's good at driving the gaps. His double-plus speed will help him leg out extra-base hits, as well as swipe some bags and cover plenty of ground.

Jebb has split his time between shortstop and second base. He projects as an average defense shortstop, but has an arm that might play better on the right side of the infield. Jebb's speed also leads some to believe he could move to center field, if the need arises. Jebb logged a handful of games at third base during his time in the Cape Cod League, adding another position to his resumé.

Jebb's ability to make contact and draw walks, combined with his speed, make him a potential future leadoff hitter. He should be able to play up the middle long term as well, whether that be second base, shortstop, or center field. That could also give him some potential utility in the field as well.

Number Nine: Levi Sterling

Our next prospect is a new arrival from the 2024 draft class, and one of many top pitching prospects in the Pirates' system: Levi Sterling. The Pirates selected Sterling 37th overall out of Notre Dame High School. He signed a deal worth just over $2.5 million to forgo his commitment to Texas. A projectable right-hander, Sterling adds yet another talented arm to a system that is loaded with pitching.

Sterling is sitting around 90-92 MPH (tops 94) with his fastball at just 17 years old. He won't turn 18 until early September. Sterling throws a pair of breaking pitches. His curveball is the better pitch, a mid-70 pitch he puts a ton of spin on. In contrast, he throws a low-spin changeup around the low 80s. His second breaking pitch is a low-80s sweeping slider, giving him four pitches with average or better potential.

Sterling has a lot of attributes that gives him a potentially bright future. One is that he commands his stuff well. The second is that he throws from a low three-quarters arm angle. He can also keep up the same arm speed. Sterling has a projectable frame as well. He stands at 6'5", 202 pounds. 

Given that, Sterling will be an interesting player to watch once he hits the pro scene. He may not pitch this year, but you should look forward to seeing what he does at the Florida Complex League or Dominican Summer League next season. 

Number Eight: Hunter Barco

The Pirates took Hunter Barco in the second round of the 2022 draft, knowing he wouldn't be ready right away. He had undergone Tommy John surgery in his final year at the University of Florida. He wouldn't return until the second half of 2023, but his workload was very limited. He only pitched 18.1 innings in nine appearances. It was a promising small sample size, however, as Barco had a 3.44 ERA, 1.79 FIP, and 1.25 WHIP at the end of the 2023 campaign.

2024 has been Barco's first extended look at the professional level, and so far, it's been very good. Barco has logged 66 innings between Greensboro and Altoona, working to the tune of a 3.27 ERA, 3.36 FIP, and 1.06 WHIP. Opponents have managed a meager .202 batting average against him and a 0.68 HR/9 rate. The southpaw has struck out over 30% of his opponents, carrying a 31.2% K% with a respectable 8.3% walk rate.

Barco's strong season at Greensboro earned him a bump to Altoona in July. Although he landed on the IL in his second start, he was looking good, pitching four innings, allowing just a single earned run, and striking out six batters (against no free passes) in his first two games.

Although Barco isn't a flamethrower, he sits 92-94 MPH from a low arm slot with his sinker. Along with a two-seamer, he'll also throw a four-seamer. His slider is his best pitch, an offering that sits in the low 80s. His offspeed pitch is a changeup that also has above-average potential. Barco can also locate his variety of pitches well. Plus, his crossfire delivery adds some deceptiveness.

Barco is already 23, and now that he's at Double-A, he has a real shot of being a major contributor to the 2025 club, assuming he isn't traded in the offseason. He has come back strong from Tommy John surgery in 2022, and he's looking like one of the Pirates' many potential rotation options for the long term.

Number Six: Zander Mueth

Many eyes were obviously focused on Paul Skenes in the 2023 draft. But the second pitcher the Pirates took, Zander Mueth, also deserves some attention. He's a funky right-hander with good stuff and projectability, making him one of the Pirates' highest-ceiling pitching prospects right now.

Mueth made his pro debut in the Florida Complex League, where he pitched 51.1 innings and worked to a 1.58 ERA, 4.14 FIP, and 1.27 WHIP. He held opponents to a batting average around the Mendoza line at .204 while inducing ground balls 49.6% of the time. That also helped him post a home run rate of just 0.35. Mueth struck out nearly a quarter of opponents with a 24.9% K%, but he struggled to limit walks with an 11.6% BB%. Mueth was then promoted to A-Ball Bradenton, and his first two appearances haven't been pretty. He's only pitched 4.2 innings and has allowed two earned runs, striking out just four and walking nine. 

Mueth's primary pitch since reaching Bradenton has been his sinker. This pitch has averaged out at 93.4 MPH with 14.6 inches of arm side run and 21.6 inches of vertical movement, and is considered his best pitch. His mid/upper 80s slider has about 35 inches of drop and grades out as his best breaking offering. His low-spin/mid-80s changeup has averaged out with 37.1 inches of drop and 14.8 inches of break.

However, Mueth's stuff plays up because of his deceptive delivery. He throws from a side-arm arm slot, similar to Tanner Houck or Chris Sale. Mueth releases the pitch about seven feet in front of the mound, which makes his pitches look about one MPH faster out of the hand, making a 94 MPH sinker look like 95-96 MPH.

Mueth is also projectable with good physical traits. He is an imposing 6'6", 205-pound presence on the mound. He also just turned 19 in June. At his size and age, Mueth could definitely add another tick or two of velocity over the coming years, making his already hard sinker look even faster.

While the control/command definitely needs work, there's plenty of time for him to refine both. His stuff, size, and deceptiveness make him one of the highest-ceiling prospects in the system. It will be fun to see what he can do in a full season.

Number Five: Braxton Ashcraft

Heading into 2023, there were questions about Braxton Ashcraft's long term outlook. He barely pitched from 2020 through 2022, missing time because of the canceled COVID season, as well as myriad injuries. He then returned in '23 and posted impressive numbers, albeit while being limited and only pitching 52.2 innings in 19 outings.

Ashcraft has gotten more work in during 2024, already pitching 72 frames between Altoona and Indianapolis, and he's been great. He has a 2.88 ERA, 2.94 FIP, and 1.07 WHIP. Ashcraft has struck out 25.9% of opponents with a sub-5% walk rate of 4.1%. This has led to an elite 6.62 K:BB ratio, the 13th best among minor-league pitchers with at least a dozen games started. 

Ashcraft was sitting 94-96 MPH with his fastball in 2023, and many wondered if he could maintain that velocity. So far, that hasn't been an issue in 2024. This pitch also has a plus ride through the zone. The right-hander utilizes an upper-80s slider with nearly 32 inches of break. Although his four-seamer and slider are his best offerings, Ashcraft also possesses a low-80s curveball with 51.5 inches of drop. He's also tinkering with a changeup, which is easily his worst offering.

There's no question about Ashcraft's ability to locate in the zone. He has the eighth-best walk rate of any minor-league pitcher since the start of 2023 with at least 25 games started, sitting at 4.5%. He is only one of nine pitchers with a sub-5% BB% in the same time frame, and the same minimum number of games started.

Ashcraft's huge comeback and further success has been massive for the Pirates' future outlook. The Pirates opted to protect him from the Rule 5 draft by placing him on their 40-man roster this past offseason, which puts him right on the doorstep of the big leagues. If Ashcraft isn't out for very long, we could see him at least make his major league debut this season.

Number Four: Thomas Harrington

Prior to the Pirates selecting Hunter Barco in the 2022 draft, they took right-hander Thomas Harrington out of Campbell with the 36th overall selection. Harrington made his mark in 2023 between A-Ball Bradenton and High-A Greensboro. Although he missed the first month of the 2024 campaign, Harrington has come back stronger than ever and was recently promoted to Triple-A Indy.

Prior to that promotion, however, Harrington owned a 2.14 ERA, 2.56 FIP, and 0.98 WHIP through his first 71.1 IP. He maintained a strong strikeout rate of 27.6%, almost identical to last season, but he impressively cut his walk rate to just 3.9% (compared to 7.8% last season). Harrington also made improvements in the home run prevention department, going from an 0.99 HR/9 last season to just 0.50 prior to his call to Indy.

Harrington has already made his Triple-A debut, but it didn't go smoothly. While he pitched 5.2 innings, striking out four and only walking a single batter, he also allowed a home run and five earned runs total. Of course, it's a one-game sample size in a much more hitter-friendly environment, so take it with a grain of salt.

Harrington threw five different pitches at least 10% of the time in his first game with Indianapolis. His low-90s four-seamer may not have elite velocity, but its movement and Harrington's arm angle help it play up. Harrington's best secondary is his low-80s slider. This was a pitch he improved as he got into pro ball, going for more of a sweeping slider compared to what he was throwing in college. So far, it's worked tremendously well for him.

Harrington's next breaking ball is a curve that sits in the upper 70s. His changeup averages out to around 1,000 RPM. Harrington's sinker has similar velo to his fastball, but with more downward action. Harrington projects to have plus command, and given his sub-5% walk rate this season, he's had no trouble locating so far in his career.

Now that Harrington is at Triple-A, he could be on the verge of making his big league debut. The Pirates could definitely be in a good position to utilize him as another reinforcement late into the season. 

Number Three: Termarr Johnson

The Pittsburgh Pirates' first-round pick in 2022 was infielder Termarr Johnson. Taken fourth overall, Johnson was signed to a huge deal worth $7,219,000 which, at the time, was a record-breaking amount for a fourth overall pick. Johnson has had some ups and downs, but there've been way more positives than negatives to his tenure, and his ceiling is super high.

Johnson's 2024 got off to a poor start. His first 154 plate appearances saw him bat a mediocre .175/.383/.245 with a .329 wOBA and 103 wRC+.Johnson struggled to hit for much power and had just an .079 isolated slugging percentage. The only positive was that his plate discipline was great. He had a solid 22.7% strikeout rate, but walked 22.1% of the time, but that's about where the positives end during this stretch. 

But since then, Johnson has put things back on track. His most recent 282 plate appearances have yielded a .277/.388/.464 line, .390 wOBA, and 141 wRC+. The power has started to come around, given his .187 isolated slugging percentage. Although Johnson is walking less frequently, he still has an elite 14.2% BB%. Plus, he's dropped his strikeout rate below 20% at 19.9%.

Despite his smaller stature of 5'7", 175 pounds, Johnson projects to hit for plus power. He displayed a strong hit tool throughout his high school career, but while it's taken a while for him to get used to pro ball, the potential is still there. Johnson has split his time between shortstop and second base. Between the two positions, his speed and arm project better at the keystone.

With how well Johnson is performing right now, it wouldn't be a surprise if he gets promoted to Double-A before the end of the season. He's still only 20 years old and won't turn 21 until June of next season. There's a possibility that he could be in the big leagues before the end of 2025, giving the Pirates yet another potential long-term middle infield option.

Number Two: Konnor Griffin

Our second-best Pittsburgh Pirates prospect is their most recent first-round pick, Konnor Griffin. The Pirates had the ninth overall selection in this year's draft and used it on what many considered to be the highest-ceiling prospect in the draft. He was the top-ranked high schooler and brings a ton of talent to the organization.

Drafted out of Jackson Prep, the Pirates inked Griffin to a deal worth just over $6.5 million to convince him to sign instead of attending Louisiana State University. Heading into the draft, Griffin stood at 6'4", 210 pounds, with his primary positions being shortstop and center field. He also pitched some, touching 96 MPH on the mound.

His size helps him generate good raw power, with the potential to hit for plus power in the future. He's a potential double-plus runner, and the arm that he showed off on the mound lets him make deep throws from the left side of the infield or from the outfield.

Griffin's hit tool is the worst part of his game, but it still projects as average. His swing is long, but he's recently improved his swing decision making. Given he just turned 18 in late April, there's plenty more time left for him to improve upon this.

Griffin is a potential 30/30 threat with Gold Glove potential at the most premium non-catcher positions on the field. If Griffin reaches anywhere close to his ceiling, he's a true middle-of-the-order threat who can equip future Pirates teams with a strong defender.

Number One: Bubba Chandler

Given how much pitching is in the Pirates' system, it's no surprise Bubba Chandler was our consensus number one Pirates prospect. The 2021 third-round pick signed the second-highest signing bonus of any third-rounder. This allowed the Pirates to pry him away from his commitment to play football at Clemson. Plus, Chandler was drafted as a two-way player coming out of high school. This was something the Pirates experimented with early in Chandler's pro career, but dropped entirely last season.

Chandler had some bumps in the road adjusting to pitching full-time, but had an outstanding second half in 2023. That's carried over into 2024. Chandler tossed 80.1 innings for Altoona, working to a strong 3.70 ERA, 3.27 FIP, and 1.01 WHIP. Chandler struggled with command early in his career, but has since improved dramatically. He's cut his walk rate down to just 8.1% this season, and he's done so while maintaining a strikeout rate of nearly 30% at 29.4%. He also has not allowed many home runs, with an 0.78 HR/9.

Chandler has looked unstoppable recently. Since the start of June, he has a 2.61 ERA, 2.31 FIP, and 0.79 WHIP. He has a walk rate under 5% (3.1%) with a strikeout rate over 30% (31.6%) over his last 51.2 IP. Chandler has allowed just three home runs as well during this summer.

Chandler continued his dominance in his first Triple-A appearance, tossing seven shut out innings, allowing just one hit, one walk, and striking out six batters. Chandler was touching the upper 90s, topping out at 98.7 MPH.

There's never been any questions about Chandler's stuff. He sits mid-upper 90s with his four-seamer and has topped out at triple-digits before. His four-seamer also has good movement, with just 11.8 inches of drop in his Triple-A debut. His upper-80s slider is his primary breaking pitch, giving him a second pitch with at least above-average potential. Chandler has made major strides forward with his changeup in terms of command. Chandler also has a fourth pitch: a curveball he'll mix in from time to time as well.

Drafted as a RHP/shortstop, Chandler is extremely athletic on the mound. He's been putting that athleticism to good use, improving his command and getting his motion in check. His ability to improve his control and command has helped propel him to the number one spot on our top Pirates list, as well as Baseball America's, MLB Pipeline's, and FanGraphs'.