The Texas Rangers have an incredibly unique developmental project brewing in Arizona, with two, two-way players: Josh Owens and Seong-Jun Kim. Many fans following the Rangers farm were curious about when Seong-Jun Kim would take the mound. Tonight, that question was answered as he made his highly anticipated pitching debut this season for the ACL Rangers.
Facing off against the ACL Rockies, the 19-year-old international standout showed exactly why his high-ceiling has generated so much intrigue within the player development staff.
Kim took the mound for a single, controlled frame and was absolute perfection, dominant and efficient. He didn't allow a single hit or walk, retiring the side in order to lock down a scoreless outing.
Inside the Velocity and Pitch Sequence
The right-hander attacked the zone with an electric pitch mix, throwing 8 total pitches—6 of them for strikes—while relying heavily on his four-seam fastball before pulling the string on a sharp breaking ball. He threw 7 fastballs and just a single slider.
Thanks to Statcast data, we can see the exact breakdown of how Kim carved up the ACL Rockies:
- Pitch 1: Four-Seam Fastball (94.4 mph) — Groundout to second base (80.4 mph exit velocity)
- Pitch 2: Four-Seam Fastball (94.1 mph) — Called strike (0-1 count)
- Pitch 3: Four-Seam Fastball (95.5 mph) — Groundout to shortstop (85.6 mph exit velocity)
- Pitch 4: Four-Seam Fastball (94.9 mph) — Ball (1-0 count)
- Pitch 5: Four-Seam Fastball (92.4 mph) — Called strike (1-1 count)
- Pitch 6: Four-Seam Fastball (94.3 mph) — Foul ball (1-2 count)
- Pitch 7: Four-Seam Fastball (94.7 mph) — Ball (2-2 count)
- Pitch 8: Slider (83.6 mph) — Swinging strikeout to end the inning
His fastball topped out at 95.5 mph, and his final pitch was a 83.6 mph slider.
Tearing It Up at the Plate
Prior to making his season debut on the mound tonight, Kim has spent the bulk of the 2026 season serving as the DH for the ACL Rangers' offense. He has played four games at Shortstop.
Through 27 games this season, Kim is slashing .298/.394/.524 with a .918 OPS. His advanced approach and power have translated into 4 home runs and 20 RBIs, alongside 14 walks and 31 strikeouts in 84 at-bats.
True two-way development is still rare in professional baseball, but the Rangers' patient approach seems to be paying off early on. Whether he's driving balls into the gaps, or sitting in the mid-90s on the rubber, Kim is one of the most electric names to watch at the complex.
