Pittsburgh Pirates Prospects: Top Age-20 and Below Talents

Position Players

The Pirates' best under-20 catching prospect is Axiel Plaz, who could eventually become one of the team's best prospects. Plaz is just 17 and won't turn 18 until August 12th. Plaz's first look at the Dominican Summer League could not have gone any better. It was only 86 plate appearances, but the young backstop batted .382/.500/.706, with a wOBA clocking in at .550 and wRC+ over 200 at 209. He racked up three home runs, an impressive amount of doubles (11) with a 13:16 BB:K ratio.

Plaz has already gained some prospect notoriety, as Baseball America ranked him as the Bucs' 28th-best prospect. Plaz's defense was considered his strong suit, but with decent offensive upside. It will be interesting to see how Plaz develops going forward. 

The best overall infield prospect the Pirates have is Termarr Johnson. Johnson was the team's first-round draft pick from this past season. He was considered one of the best prep hitters in recent draft history, with MLB Pipeline comparing his plate discipline and plate coverage to Wade Boggs and Vladimir Guerrero Sr., respectively. He also runs well, and don't let his 5'7", 175 pounds stature fool you. He hits for above-average to well above-average power because of his lightning-quick bat speed.

Johnson is a guy who could consistently hit .300/.400/.500 each season. He also has the speed and power to be a 20/20 guy, at least. The only question is what middle infield position he'll play long-term. Johnson makes the routine plays at shortstop, but his arm is fringy at best, and he will have some difficulty making some of the deeper plays. The Pirates drafted him as a shortstop, and although he played some short in his first look against professional opponents, he mostly lined up at the keystone.

One of the most interesting prospects the Pirates have to offer is Tony Blanco Jr. The Pirates signed the young outfield prospect during the 2021-2022 international signing period, and he comes with the power potential of someone like Giancarlo Stanton. Blanco Jr. already stands at 6'4", 245-LBS before his 18th birthday (currently 17 and won't turn 18 until May 14th). Speaking of Stanton, that is the same weight Baseball Reference currently lists the Yankees' DH/OF at, and just two inches taller. That kind of size gives him a sky-high ceiling but a risky floor.

Blanco struck out ten times in his injury-shortened 19 plate appearances at the DSL. He's already not considered a fast base runner, but he does at least have an arm to play an outfield corner. Granted, even Stanton was considered average to above average in terms of speed in his first handful of seasons. But depending on how Blanco develops, he might have to move to first base long-term.

The third player on this list the Pirates signed out of the 2021-2022 international market is Yordany De Los Santos. The infielder slashed .258/.372/.363 with a .368 wOBA and 106 wRC+ through 234 plate appearances at the Dominican Summer League. De Los Santos had a strong 13.7% walk rate and 19.2% walk rate but did not hit for much power. He only bopped one home run and had an ISO of .105. He also had nearly as many walks (23) as strikeouts (24) and a 130 wRC+ from July 9th through the end of the year.

Despite his low power output in his first look at the DSL, De Los Santos projects to have 60-grade power, per FanGraphs. His hit tool also comes out to about average, but like Johnson, his final position is yet to be determined. There's some concern that once he fills out his 6'1", 170 pounds frame, he'll have some trouble with his range at shortstop. He certainly has the arm to play on the left side of the infield, and on the plus side, he did show some improvements in terms of defense last season. If he can continue to make those improvements and keep his range up, he won't have to move off of shortstop.

Shalin Polanco is the longest-tenured player we'll look at today. The Pirates signed Polanco as an international signee in the 2020-2021 off-season. Polanco has spent the last two seasons with the Pirates' short-season affiliates (DSL and FCL), turning in a mediocre .225/.303/.353 line, .320 wOBA, and 86 wRC+. He's walked at a respectable 9.3% rate but has struck out just over a quarter of the time (25.3% K-rate) and has an isolated slugging percentage of .128.

MLB Pipeline is still bullish on the left-handed hitting outfielder, however. He's still a projectable 5'11", 168 pounds, and has shown off some decent bat speed. If he can add some muscle behind that bat speed, Polanco could end up with above-average game power. He also grades out as an average to above-average runner and defender with a solid arm. He's shown off an overly aggressive approach at the plate, leading to a higher strikeout rate. 

Pitchers

The Pirates added what is likely their best under-20 prospect this past off-season when they signed Jun-Seok Shim at the international signing deadline. Shim opted to head to the United States instead of partaking in the Korean Baseball Organization's draft. Shim is a 6'4", 215 pounds right-hander who will turn 19 two days after PNC Park Opening Day (April 9th). Shim is known for his big fastball that sits mid-upper-90s but has hit triple-digits. His curveball has a 12-6 shape, and both his slider and change-up project as average.

Not only does he have a strong arsenal of pitchers, but he has a ton of makeup. Shim is an athletic pitcher. On top of that, he has clean mechanics, which are two factors that will help his command improve over time. He already has a feel for the strike zone, so he could develop above-average command by the time he's 21-22 years old.

The Pirates' next best teen pitching prospect was another arm they added fairly recently, that being Michael Kennedy, the Bucs' 4th round pick from 2022. Kennedy is a southpaw from New York who has a three-pitch arsenal. That includes a fastball, slider, and change-up. His fastball currently sits in the upper-80s/lower-90s and tops out at 92 MPH. He's still young, as he only turned 18 on November 30th, but he'll never be a flamethrower. He mostly uses deception and ride to make the pitch play to an above-average level. Even then, if he can sit 91-93 MPH in the future, he'll make his fastball a very good offering. Kennedy throws an upper-70s slider that gets swings and misses, as well as a change-up.

Kennedy has a clean and repeatable delivery, showing a good ability to command his stuff. He's one of the youngest players we'll talk about today, so he still has ways to go before he even gets to Altoona. That means there is still some projection left for the southpaw, which is only beneficial for him in the long run.

Other Prospects To Know

These prospects aren't on many prospect lists, as the ones we went in-depth with were on FanGraphs or MLB Pipeline's Pirates' top prospect lists. However, the Pirates have plenty of other young prospects that fans should know about, starting with Andres Silvera.

Silvera pitched 41 innings for the Pirate DSL team, working to a 1.54 ERA, 2.13 FIP, and 0.89 WHIP. He struck out 29% of the opponents he faced with a walk rate of 3.9%. Even better was his 55.3% ground ball rate and not allowing a single home run. Silvera only works around 88-90 MPH, but given he won't turn 20 until July of 2024, there's still time for him to add size and strength to his 6'0", 188-LBS frame.

One of the team's highest-paid 2021-2022 international signees was Pitterson Rosa. In Rosa's first 22.1 innings, the right-hander allowed eight earned runs and walked 11 batters. However, he didn't let up a single home run and struck out 24. Rosa, like nearly all the players we've looked at, has a projectable frame, standing in at 6'2", 180 pounds. But Rosa is already topping out at 94 MPH, and is a converted outfielder, so he has some athleticism to go with the projection.

Inmer Lobo is a 19-year-old left-hander the Pirates acquired this past off-season from the Boston Red Sox in exchange for utility man Hoy Park. Lobo pitched 22 innings for the Sox DSL affiliate, allowing just two earned runs on two walks, 15 hits (just a single home run), and striking out 28. Lobo, like Silvera, only sits around the upper-80s/low-90s. His season was cut short by an injury, but he will be interesting to watch at the FCL next season.

Miguel Sosa is yet another catching prospect to keep an eye on at the FCL. In 109 plate appearances, Sosa batted .305/.468/.512 with a 166 wRC+. Sosa walked more than twice as often as he struck out (25:12 BB:K ratio), and 11 of his 25 hits went for extra bases (eight doubles, three home runs). Sosa split his time between the backstop and left field at the DSL last season. He has some athleticism and a strong arm, along with decent raw pop.

Jesus Castillo was the batting champion at the FCL, slashing .352/.439/.383 through 150 plate appearances. Castillo struck out just 18 times and drew 17 walks. But his power amounted to just four doubles and an ISO below .050 at .031. Castillo, a middle infielder, is a stout 5'9", 145 pounds. He makes a lot of contact but is held back by his lack of power.