Pittsburgh Pirates Triple-A players who could soon get promoted to the Major Leagues

The Pittsburgh Pirates are in a rut right now. At the time of writing this, they just ended a six-game losing streak. Something will probably change in terms of roster construction in the next week if something doesn’t change (of course, there are much larger changes I’d like to see). The Pirates could definitely use a hot bat and another relief arm to further bolster their bullpen, as they’ve been an inconsistent group to start the year.

Several standout performers from the Indianapolis Indians have caught the attention of the Pirates' management, demonstrating promising potential for the big leagues. With the Pittsburgh Pirates aiming to bolster their roster with talent from their Triple-A affiliate, the performances of these players serve as a testament to the depth and skill within the organization's farm system. As fans eagerly anticipate the call-up of these rising stars, the Indianapolis Indians serve as a crucial developmental ground for future success in Pittsburgh.

Kyle Nicolas

The Pirates will probably make a move to bring up two relievers over the next week. Hunter Stratton struggled mightily in his most recent game, and Ryder Ryan has been awful. While Mlodzinski and Heller are definitely options, Kyle Nicolas should also be on the docket for a potential promotion. Acquired via the Jacob Stallings trade in the 2021-2022 off-season, I thought that Nicolas would have an inside track for one of the last bullpen spots, but with his hot start to the year, he definitely should be in the conversation for the next reliever up.

So far in 2024, Nicolas has pitched 10.2 innings, striking out 13, allowing two hits and one earned run. However, walks have been giving him some issues. He’s handed out nine free passes, though his control looked much better last year, and it’s still a small sample size so far in the minor leagues. Nicolas struggled badly in his first Major League game last season but then pitched five innings, allowing one earned run and striking out seven with just two walks.

Nicolas also had a strong run of games late last season. In the 15 innings he pitched prior to his MLB promotion, the right-hander had a 1.20 ERA, 2.64 FIP, and 0.80 WHIP. He had a solid 10.3% walk rate but struck out over 40% of the batters he faced with a 41.4% K% and allowed only one home run for a 0.60 HR/9.

Nicolas is still sitting 96-97 MPH and topping out at 99. He’s also throwing with a lot of movement. I’ve previously made the comparison to Gerrit Cole and his four-seam fastball. Both throw with about the same velocity (Cole sat 96.7 MPH last year), with about the same vertical ride (11.6 inches on Nicolas’ four-seamer, 12 inches on Cole’s), and horizontal break (8.8 for Nicolas, 8.4 for Cole).

Along with an elite fastball, he mixes in two breaking pitches. One is a curveball that sits in the low 80s. But the better of the two breakers is his slider. This pitch sits in the 88-90 MPH range but has an incredible 59.1% whiff rate so far in the short season. This offering from Nicolas typically sits with around five inches of horizontal break.

Nicolas has some potent stuff on the mound. His control has been a little inconsistent to start the year, but he showed improvement down the stretch last year and in the Majors during his brief September promotion. We shall see if Nicolas will get the call.

Ben Heller

The Pirates signed Ben Heller to a minor league deal throughout the off-season. Heller made a brief appearance in the Major Leagues last season for the Atlanta Braves, mostly pitching in low-leverage situations. Heller had an outside chance to make the Pirates’ Opening Day roster heading into camp, but injuries sidelined him for all of Spring. But he’s back in action and could put himself into contention for a bullpen spot.

Heller pitched most of his season at Triple-A, where he had a 3.27 ERA, 3.35 FIP, and 1.23 WHIP through 44 frames. This included a 28.9% strikeout rate, a 7.6% walk rate, and 0.41 HR/9. Heller induced a ton of grounders with a 51.4% GB%. Combined with a line-drive rate below 20% and flyball rate under 30% and it’s no wonder why he allowed so few home runs.

Heller then went on to pitch 18.2 innings in the majors with Atlanta where he had a middling 3.86 ERA, 5.02 FIP, and 1.45 WHIP. While he was still inducing ground balls at a healthy 49.1% rate, he had a K% below 20% at 19.6%, as well as a walk rate of 13.4%. Heller also pitched for the New York Yankees from 2017-2020, aside from 2018.

But the pitch that could carry Heller in the Majors is his sweeper. The pitch was unhittable last year, and I’m not exaggerating. He threw his sweeper 41 times during the 2023 season. Not one time did batters get a base hit off of it. His 78.6% whiff rate is the highest single-season whiff rate on any pitch in the Statcast era (since 2015). But don’t sleep on his mid-90s sinker that has well above-average movement.

Heller’s rehab has gone excellent. He has pitched five innings, has not walked a batter, only two have reached via base hit, and has struck out nine. Batters’ sticks are still allergic to his sweeper, with a 69.2% whiff rate. Currently, that’s the 3rd highest whiff rate among all minor leaguers who have thrown a sweeper at least ten times so far.

With how good Heller’s sweeper is, we could definitely see Heller as an option in the Major Leagues sometime this year. I don’t know if he would take priority over Nicolas or another name we will soon talk about, as they are both on the Bucs’ 40-man roster. But he’s definitely making a push to get his time in the big leagues in 2024.

Nick Gonzales

While Nick Gonzales was riding a hot streak prior to getting called to the big leagues, both times, he struggled once he got here, batting .209/.281/.348 with a .267 wOBA and 64 wRC+. He struck out 28.1% of the time, but more worrying was his 4.7% walk rate. But Gonzales, who opened the year back at Triple-A, has gotten off to a scorching hot start.s

Through his first 85 plate appearances of the season, the infielder is batting .385/.435/.590 with a .451 wOBA and 165 wRC+. He is only one of 26 batters at Triple-A right now with an OPS above .900, wOBA above .400, and wRC+ above 150. Although he only has one home run, he already has 11 doubles. Gonzales has only drawn five walks, however. This has led to a walk rate of just 5.9%. That’s compared to last year when he had a 12% BB%.

Strikeouts were an issue that Gonzales has faced since making his pro debut. But at the time of writing this, Gonzales has not struck out in three straight games. In total, he’s had nine games without a K. Last year, he only had 27 games without a strikeout at Triple-A in games where he had at least four plate appearances. He has gone down on strike three just 14 times for a K% of 16.5%.

That currently ranks in the top 50 among Triple-A hitters. He’s also hitting much better against breaking and off-speed stuff with a .333/.350/.436 with a .348 wOBA. His 35.7% whiff rate is still a tad high, but a noticeable improvement from 39.1% the year prior, and also not much worse than the league average 33.2% whiff rate on the same pitches across all of Triple-A.

We shall see if he can continue those improvements if or when he makes the big leagues. It’s definitely promising to see he’s not being fooled nearly as often on breaking/off-speed stuff as he has in previous seasons. This new contact-focused approach could work very well for Gonzales. I definitely think he’s the sort of player who would succeed with it.

Carmen Mlodzinski

Ben Heller nor Kyle Nicolas aren’t the only relief pitchers eyeing a return to the Major League mound. 2023 standout rookie Carmen Mlodzinski has since returned from his own injury list stint and has to be on the cusp of receiving his promotion back to the Major Leagues. Mlodzinski opened the year on the IL, and was then optioned to get him stretched out. But now that he looks back at full health, the Pirates should be getting back one of their best relievers from the second half of last season.

Of Mlodzinski’s 35.1 innings pitched last year, 23.2 were after the All-Star break. During that stretch, the former first-round pick owned a quality 2.22 ERA, 3.34 FIP, and 1.36 WHIP. While he had a 12.5% walk rate, he also had a respectable 24% strikeout rate and was great at preventing good contact. He held batters to a minuscule 1.5% barrel rate, tied for the fifth lowest among all relievers last season in the second half.

So far, Mlodzinski’s rehab has gone well. He has pitched seven innings, striking out seven and allowing only three earned runs. Granted, two of those runs came in one game, and he’s now tossed three straight scoreless outings. Both of his walks also originate from one game, with going 5-6 in walk-less appearances.

Mlodzinski’s cutter looks significantly different. While he’s taken some velocity off the pitch, dropping from 91-92 MPH last year to around 86-88 MPH, he’s added about three inches of drop and break. Currently, he has a 38.1% whiff rate on the pitch. His four-seamer also has slightly less velo but more ride and break. His sweeper has about the same movement and velo profile, as does his change-up. 

It’s a bit of a surprise that the Pirates haven’t called up Mlodzinski yet. He played a key role in the Pirates’ bullpen during the second half of the year. When Colin Holderman went down with an injury in September, Mlodzinski stepped into the set-up role and performed admirably. But with guys like Stratton and Ryan struggling, it probably won’t be long until we see Mlodzinski back in the bigs.

Ji Hwan Bae

Speedy utility man Ji Hwan Bae played semi-frequently for the Pirates in 2023. However, he struggled greatly. In 371 plate appearances, Bae hit .231/.296/.311. While Bae was a plus on the basepaths, he wasn’t able to fully capitalize on his speed given his sub-.300 OBP. He had an okay 8.1% walk rate and 24.8% strikeout rate but hit for very little power. Bae had a sub.-100 isolated slugging percentage and went 337 straight plate appearances without a home run. Overall, he had just a 66 wRC+.

Bae spent a good portion of his season in center field for the Pirates, where he displayed solid defense and improved route running.

At the end of the season, he only had -1 defensive run saved, but a +2.8 UZR/150 and +3 outs above average. His defense at second base, however, wasn’t great, and he had -6 DRS and -2 OAA.

Bae had a chance to secure a Major League roster spot to open the year and got off to a hot start in Spring Training. But he suffered a hip injury and was placed on the IL in just the first week of March. Bae, now in rehab, has gotten off to a great start. He has 35 plate appearances between Bradenton and Indy, where he has 13 hits with the same amount of strikeouts to walks with seven each. Bae also hit a home run nearly a full calendar year from his last home run, which was a dramatic walk-off against the Houston Astros.

Now, here’s something that stands out about Bae’s metrics. He has a 95.3 MPH exit velocity and a 55.6% hard-hit rate. Bae had just an 88.1 MPH exit velo and 36.8% hard-hit rate in the Majors last season. His launch angle is also up significantly from 1.1 degrees to 8.1 degrees. It might not seem like much, but a batted ball with an 89 MPH exit velo and two-degree launch angle results in a hit about 34.3% of the time, while a batted ball with a 95 MPH exit velo and eight-degree launch angle goes for a hit 61.3% of the time. Bae is also rarely swinging and missing. He has a whiff rate of just 16.7%.

Now is this a microcosm of a small sample size? Probably. But if Bae can translate even a fraction of that improved power to the Major Leagues. A six degree launch angle with an 89 MPH exit velocity would be a massive improvement from last year. I don’t know who at the Pirates needs to hear this right now, but more hard-hit baseballs plus fewer swings and misses plus lifting the ball is a combination that can be very successful.