When a debut goes exactly to plan, you might call it beginner’s luck. On Friday night, Seth Hernandez, the Pirates’ top pitching prospect, took the mound for his second start for Single-A Bradenton and proved that his Florida State League Opening Day outing was anything but an aberration.
The 19-year-old threw four hitless innings, lowering his ERA to 1.29. He allowed one walk while striking out seven, displaying an unhittable sinker in the process. Despite his efforts, the Marauders ultimately fell 7-3 to the Palm Beach Cardinals to kick off Opening Weekend at LECOM Park.
Hernandez, who was drafted sixth overall in the 2025 MLB Draft, established himself as the best prep arm in his class while dominating the Southern California circuit at Corona High School. He joined the Top 100 Prospects list before even making his first pro start. Now ranked No. 26, his Bradenton debut came with plenty of fanfare -- and it was well-deserved.
Still on a pitch count, the 6-foot-4 righty racked up 18 whiffs on 24 swings, striking out eight batters in the process. His 75 percent whiff rate has only been achieved once in the Florida State League since 2021 when Statcast was installed.
"I was really just trying to throw as hard as I could, and it was getting some good whiffs," Hernandez said of his slider/cutter hybrid last week. "Especially to the lefties too, because before, I've never really thrown a lot of sliders to the left-handed batters as much."
His second go-around displayed the same swing-and-miss stuff with 14 whiffs across his four innings of work. Much of his success came on his sinker, which hit over 100 mph twice on the radar gun, while topping 99 an additional six times. But the velocity is only one piece of the story. His sinker also averaged 16 inches of induced vertical break, already right around the MLB average, and it either was a called strike or whiff 52.2 percent of the time.
It’s easy to forget that Hernandez is less than a year removed from high school. With the player development staff and resources that have produced top-flight prospect arms like Paul Skenes and Bubba Chandler, the ceiling for Hernandez could find another tier.
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