16. Jackson Cox (284 points, 19 ballots)
Cox was Colorado’s second-round pick in 2022, 50th overall, out of a rural high school in Washington state. To get Cox out of his commitment to Oregon, the Rockies signed the 6’2” righty starter for a $1.85 million bonus — well over the pick’s $1.54 million slot value. Cox’s calling card as a prospect is his 3,000+ RPM curveball, described as a slurve with “deep and late bite” which the now 22-year-old paired with a low- to mid-90s fastball and a developing change-up in a repeatable delivery. When healthy. Which he hasn’t been much, though in 2025 we saw Cox on the mound regularly again.
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Mid-season 2025 Rank: 25
High Ballot: 4
Mode Ballot: 13, 16
Future Value: 40, back-end starter
Contract Status: 2022 Second Round, Toutle Lake (WA) HS, Rule 5 Eligible After 2026, three options remaining
MLB ETA: 2027
Cox was assigned to Low-A Fresno in 2023 for his professional debut, where he was 2.9 years younger than league average. The Rockies handled Cox carefully, never allowing him to go past four innings in a start or 65 pitches an outing in his ten games (nine starts). Nonetheless, Cox suffered an injury that required Tommy John surgery in July (as did fellow PuRPs Jordy Vargas and Gabriel Hughes), which ended his 2023 season and caused him to lose all of 2024 as well (he did pitch in fall instructs, just not an affiliated ball game).
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It was a long road back to Fresno in 2025 for Cox, who was still 0.8 years younger than league average. He made 23 starts but was handled carefully, not passing the three inning threshold in any of those starts until June and only exceeding five innings his final two appearances. Cox finished on a high note, twirling a Quality Start of six innings, one run on two hits and two walks with six strikeouts on a season-high 92 pitches.
In total, Cox threw 85 innings with a 3.39 ERA, 1.12 WHIP, 9.7 K/9 rate, and 2.6 BB/9 rate. The trajectory is good though: since a rough April, in which Cox had a 15.43 ERA, he posted a 84:19 K/BB ratio and a 2.31 ERA in 78 post April innings plus a 0.90 WHIP and .199 BAA in the second half of the season. Given the long lay-off, Rockies fans will take that even if Cox is now behind the developmental curve due to the injury.
Here’s some video of Cox from July striking out 10 batters in just four innings:
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Keith Law of the Athletic ranked Cox 4th in the system this week:
Cox was one of the three Rockies pitching prospects who went down with torn UCLs all at once in 2023, with the team announcing the trio all on the same day as if they got a bulk discount on the surgery. Cox has had the best recovery from the surgery, as his velocity and his curveball came all the way back. The Rockies gave him a slider as well, so he’s got a four-pitch mix, although he mostly throws his fastballs and curveball. He made 23 starts last year, working on very tight pitch and innings limits, so it added up to only 85 innings, but he walked just 7.3 percent of batters and struck out 27 percent even though it was his first time on a mound in two years. At worst, he should be a solid two-pitch reliever who can miss bats with the breaking ball, and there’s at least fourth starter upside here.
Cox was recently ranked 8th in the system by Baseball America as a 50 FV player and is projected to be the Rockies’ #3 starter in 2029:
Cox’s combination of present stuff and a deep arsenal stands out in an organization thin on starting pitching prospects. He attacks hitters with a five-pitch mix that includes a four-seam fastball, curveball, slider, changeup and cutter. His best pitch remains his plus curveball, a hellacious two-plane breaking ball with spin rates between 2,800–3,000 rpm that serves as a legitimate out pitch. Cox’s strike-throwing is below-average but should improve as he gets healthy.
Cox’s combination of velocity, spin and his ability to develop different pitches gives him a chance to develop into a solid mid-rotation starter in an organization that has struggled recently to develop starting pitchers.
Cox was ranked 17th in the system last January by Baseball Prospectus:
Thomas Edward John surgery sidelined Cox for the 2024 campaign as well. That’s put the 50th pick of the 2022 draft on the back foot developmentally, now entering his fourth professional season with just 10 appearances under his belt. Before his injury, Cox boasted better stuff than several pitchers on this list, albeit with some struggles in holding his mechanics together. That inconsistency may have played a role in his injury to begin with, and certainly is the type of thing you’d hope to get sorted out with innings in games. His lengthy rehab places a bigger emphasis on Cox finding and retaining his more imposing fastball/curveball combo.
MLB Pipeline ranks Cox 30th in the system as a 40 FV player with a 60 fastball and 55 curveball:
The early returns on Cox’s stuff coming back have been good, and it’s still his feel for spin that stands out. He has a plus curve with huge spin rates, 1-to-7 shape and sharp bite. He can run his fastball up to 95 mph with good life, and he has feel for what could eventually be an average changeup. Before he got hurt, he had worked on both a slider and a cutter to expand his arsenal.
Cox had added strength before the injury and there could be more in the tank the further removed from surgery he gets. He repeats his delivery well and has shown the ability to throw strikes with all of his offerings. This year will be about getting a full, healthy season in, with plenty of time to reach his mid-rotation ceiling.
Cox was listed as a prospect of note by Eric Longenhagen of FanGraphs last January:
[Cox] has a great curveball, but his below-average fastball velocity (he was 92-94 again during instructs), movement, and vulnerable plane aren’t a great fit with that curve. He’s pitched just 31 affiliated innings and struggled with control during those.
Cox seems to have found his mojo back in Low-A this past season. The next step is to do it in the upper minors and with greater length per start. Cox has a foundational breaking ball to build around and that mid 90s fastball (which doesn’t have ideal shape), making him a mid-to-back-end rotation candidate if it comes together. I ranked Cox 16th on my list at the top of my 40 FV tier due to the pedigree, stuff, and a healthy recovery in Low-A.
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Cox will be Rule 5 eligible after 2026, so the Rockies no doubt will be looking for those markers next season. I’m guessing a High-A assignment is in order to start the year but I expect at least some exposure to Double-A as well, provided the health remains.
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