Each year, certain players outside the top 10 in their team’s farm system make significant progress that boosts their prospect status. For 2026, the Diamondbacks have several such players poised to elevate their profiles and make a lasting impact. Identifying these breakout candidates ahead of time provides valuable insight into the future core of the organization.
To be considered, these athletes must currently rank outside Arizona’s preseason Top 10 prospects. This evaluation draws from Baseball America’s 2026 Prospect Handbook, highlighting players who could surprise this coming season.
Arizona’s Top Prospects Heading Into 2026
Arizona’s farm system is deep with talent. The organization’s 2026 Top 30 prospect list includes players evaluated through updated scouting reports, grades, and tools assessments. These rankings help frame where emerging players stand relative to the established elite in the Diamondbacks’ roster development.
Prospects Ready to Make a Breakthrough
Among the breakout hopefuls are two right-handed pitchers who have demonstrated distinct improvements and carry high upside: Brian Curley and Jaitoine Kelly.
Brian Curley: A Starting Pitcher with High Upside
Brian Curley’s story is one of resilience and steady growth. Initially considered undersized and lightly scouted out of high school, Curley chose Virginia Commonwealth University but sat out his freshman year recovering from Tommy John surgery. Over the following two seasons, he pitched mainly in relief before transferring to the University of Georgia, where he progressed from closer to Friday night starting pitcher.
The Diamondbacks selected Curley in the third round, signing him for an under-slot bonus of $700,000. They are optimistic about his potential as a starter but are also prepared to leverage his stuff in relief roles if necessary. His fastball, which sits between 95-96 mph and touches 100 mph, has above-average carry enhanced by a low release point and unconventional delivery angle.
Curley’s secondary pitches include an upper-80s slider notable for its depth and power, complemented by a top-to-bottom curveball and a sweeping breaking ball. He also features a fringe-average changeup. While his command is sufficient when his velocity is at peak, how he adjusts to a full five-day professional schedule is yet to be determined.
Demonstrating a combination of inquisitiveness, coachability, and confidence, Curley could see his fastball and slider improve by a full grade if transitioned to a bullpen role, making him a strong late-inning option should starting not fully suit him.
Curley’s scouting grades stand at: Fastball (60), Curveball (40), Slider (55), Control (50).
Jaitoine Kelly: A Project with Significant Starting Potential
Jaitoine Kelly entered the Diamondbacks’ radar as a projection pick, largely on his size and delivery, despite a raw arsenal and less refined secondary pitches. The younger brother of Pirates prospect Antwone Kelly, Jaitoine initially threw primarily in the upper 80s with limited secondary development when first scouted in 2023. The Diamondbacks invested $70,000 to sign him, banking on his physical tools and family pedigree.
Kelly’s fastball velocity surged notably in 2025, averaging 92.6 mph and topping out around 95-96 mph, compared to the previous year’s 88.3 mph average. His fastball generates impressive carry and extension, sometimes reaching seven feet. His best secondary pitch is a kick changeup with a sharp fade reminiscent of a splitter, although his slow, sweeping curveball grades below average and may require replacement or improvement.
Kelly features an above-average delivery and arm action and has shown significant advancements in strike-throwing command. Ongoing physical development is critical to his ability to sustain athleticism and fulfill his potential. If all elements align, Kelly could develop into a midrotation starter for Arizona.
Kelly’s scouting grades include: Fastball (60), Curveball (45), Changeup (55), Control (50).
Outlook for the Diamondbacks’ 2026 Prospects
Brian Curley and Jaitoine Kelly represent a duo of pitchers who could alter the Diamondbacks’ pitching depth chart in the near future. Curley’s versatility as both a potential starter and high-leverage reliever complements Kelly’s promising upside as a midrotation option. Their continued development will be closely watched by the organization and fans alike, as both embody the hope and determination fueling Arizona’s rebuilding efforts.
Success from such breakout candidates could accelerate the Diamondbacks’ return to competitiveness, providing cost-controlled, homegrown pitching talent that is crucial to sustained success in Major League Baseball. The 2026 season may well be a defining chapter for these players as they transition from prospects to significant contributors.
