The pitch has become an identifiable and indispensable part of Reinold Navarro’s repertoire.

But when asked about the four-seam fastball that was one of the top-performing pitches throughout Minor League Baseball this past season, the Pirates’ fascinating young lefty basically just shrugged his shoulders.

“It’s natural,” Navarro said of his unhittable heater, with Juan Guerra translating. “It’s something God gave me.”

Navarro’s fastball has drawn rave reviews from places like MLB Pipeline and Baseball America and basically every evaluator who saw the 20-year-old native of Santo Domingo, Dominican Republic.

That pitch has become as much a part of Navarro’s story as his inability to consistently throw strikes, a combination of electricity and wildness making the outcome here somewhat unpredictable.

In 24 appearances for Low-A Bradenton and High-A Greensboro this past season, including 17 starts, Navarro went 6-2 with a 2.96 ERA in 79 innings. His 135 strikeouts led all Pirates farmhands, but he also walked 70.

Looking at it another way, only three Minor League pitchers anywhere had a higher strikeout rate than Navarro (39.5%) … yet just three had a worse walk rate (20.5%) among those with at least 70 innings pitched in 2026.

“It’s outlier, elite stuff,” said Pirates director of coaching and player development Michael Chernow. “The traits on his fastball are at the top of all of professional baseball. The amount of miss he gets with his secondary pitches, despite lacking command, it’s outlier traits from a left-handed starter that are exceptional.”

Which is why the strike-throwing has been emphasized so much for Navarro, who did demonstrate “real, objective signal that his ability to throw strikes is improving,” Chernow added.

“There’s still a ton more to go, and we all know that,” Chernow said. “We’re going to continue to emphasize being over the plate with him because with the quality of stuff he has, the steadier the zone presence is, his numbers will be more ridiculous than they’ve already been to this point."

The pitch creating those absurd numbers for Navarro, his calling card to this point, is absolutely that four-seamer.

There’s upper-90s velocity, topping out at 99 mph. Scouts have noted its exceptional riding life, along with Navarro’s ability to hide the ball. Aroldis Chapman has been used as a comparison.

Overall, Navarro’s 43.6% miss rate ranked fifth in MiLB, while opponents hit just .157 against him. That’s actually up from the number (.098) Navarro produced in the Florida Complex League and during a short stint with the Marauders in 2025.

Opponents simply haven’t been able to touch Navarro, who has sometimes negated that advantage by throwing way too many balls, walking nearly a batter per inning (131 in 135) throughout his Minor League career.

The struggles throwing strikes might’ve made Navarro the ideal candidate for the Forge High Performance Camp at Pirate City.

Instead of leaning hard into on-field instruction, the Pirates decided to blend that with off-field efforts concentrating on preparation, mindfulness, breathing techniques, taking care of players’ bodies and off-field habits to fuel performance.

Navarro loved it, especially the mental skills aspect.

“It wasn’t the first time I talked to mental performance coaches, but it was the time I took it seriously,” Navarro said. “It’s been helpful in this camp because we have time to work on it.

“During the season it’s harder because we have our routines, then pitching in games. It’s helpful here because we have time to work on it.”

Expect to hear more about Navarro, as he should return to High-A Greensboro in 2027 and has the stuff to dominate. Assuming, of course, that he can control it.

As Chernow said, prospect evaluators and scouting services are starting to take notice of Navarro, because of the fastball and his elite ability to miss bats.

If they look closer, they’ll see a sharp slider and changeup that missed bats more than half the time. But how erratic Navarro has been with strike-throwing can’t be ignored.

If Navarro can use the Forge experience for good, to take the mental reset, adjust mechanics in-game and further develop his 6-foot, 178-pound frame, there’s no telling where the ceiling might reside with someone who has so much natural talent.

“I’ve been working on trying to control my mind and controlling what I can control,” Navarro said. “I’m also focused on being more athletic and getting stronger. Just working on my body so I can throw a lot of innings next year and eventually make it to the big leagues.”