Jace Jung's late-season breakthroughs against premium velocity and offspeed pitches signal a refined approach, now poised for major league opportunities.
Jace Jung’s Late-Season Adjustments Put Him in the Spring Spotlight
By the time the 2025 Triple-A season reached its final weeks, Jace Jung was no longer being evaluated on projection alone. He was being tested, by velocity, by sequencing, and by whether the adjustments he worked on throughout the season could hold up against the kinds of pitches that decide major league futures. It appeared that Jung was written off, myself included.
But according to Statcast data from Triple-A Toledo, in the second half, he could prove a lot of people wrong.
Second Half vs. Premium Velocity
Against fastballs thrown 95 mph or harder in the second half of the season, Jung produced his most encouraging velocity profile to date.
Second Half (Sep/Oct), AAA Toledo — vs 95+ mph fastballs Source: Statcast
- At-bats: 27
- Batting average: .370
- On-base percentage: .469
- Slugging percentage: .593
- Isolated power (ISO): .222
- Strikeout rate: 21.9% compared to 43% in the first half.
- Walk rate: 15.6%
- Whiff rate: 26.6% cutting that from 43.8% in the first half
- wOBA: .455
- xwOBA: .284
- Barrels: 1
The raw production exceeded the expected metrics, a gap influenced by walks and small sample size, but the underlying indicators were more important than the results themselves. Jung did not show a spike in whiffs, nor did his strikeout rate climb into a range associated with hitters selling out to catch velocity.
Instead, the profile reflected selective aggression, attacking hittable fastballs without abandoning his plate discipline.
Second Half vs. Breaking Balls and Offspeed
While velocity is often the focus, pitchers rarely live there exclusively. Jung’s second-half data against breaking balls and offspeed pitches showed that his fastball gains did not come at the expense of his broader approach, instead focusing on some key numbers like slugging percentage.
Second Half, AAA Toledo — breaking balls & offspeed Source: Statcast
- At-bats: 110
- Batting average: .255 (.181 in first half)
- Slugging: .445 (.313 in the first half)
- Whiff rate: 29.6% (37% in the second half)
What matters contextually is that Jung did not become chase-prone or vulnerable to secondary pitches as he became more aggressive against fastballs. His swing decisions remained stable, allowing his velocity improvements to layer onto an already solid foundation rather than replace it.
First Half Context: The Adjustment Point
The contrast between the first and second halves is central to Jung’s development arc.
Early in the season, Jung was more deferential to velocity, frequently allowing pitchers to dictate counts. As the year progressed, that respect turned into confidence, without sacrificing the discipline that has long defined his profile.
Swing Changes Showing Results
Detroit has emphasized swing decisions and timing efficiency throughout its system, and Jung’s late-season Statcast indicators align with that organizational philosophy. Rather than a wholesale mechanical overhaul, the data suggests refinement, improved timing, earlier commitment on pitches in his damage zone, and continued restraint elsewhere.
On paper, the swing changes Jung worked on throughout the season appear to be producing the intended effect.
A Spring Training Opportunity
Spring Training will offer Jung the chance to show that the second-half version of his game is now the baseline. Detroit does not need him to dominate statistically. It needs to see that pitchers cannot build entire game plans around velocity and escape with spin.
If those late-season trends carry into camp, Jung could emerge as one of the more compelling under-the-radar stories of the spring—a hitter who turned a long-standing question into a measurable adjustment, and then began answering it. The next step is to turn this into a major league job.
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