Arizona Diamondbacks Pitching Prospects: The Unrankable Honorable Mentions

The Players Who Could Have Made The Cut

You’ll find Patrick Forbes on nearly every major publication’s top prospect list for the Diamondbacks, but you won’t find him with a ranking on mine. I have a hard time ranking a pitcher who has yet to make his professional debut nine months after being drafted and signed. Forbes is pretty consistently ranked near the top of the D-backs pitching prospects and there are some solid reasons for doing so. He was a high draft pick, the Dbacks selecting Forbes with the 29th overall pick, receoved as compensation for losing Christian Walker to free agent. If you’re taken that high in the draft, you’ve already shown the potential for success as professional. Forbes definitely had that potential at the University of Louisville, where he touched 100mph with his fastball while utilizing a funky 3/4 deliver. He only started pitching in college, so a slower than usual development timeline is probably to be expected. Forbes’s pro debut has been delayed even further thanks to a flexor injury in early April, which will likely keep him out of games until late May at the earliest.

Dean Livingston, who was taken with the 123rd overall pick of the 2025 draft, is another pitcher who’s a ranked prospect, yet hasn’t made his pro debut yet. Unlike Forbes, he isn’t a college pitcher, instead a high schooler who didn’t crack his team’s starting rotation until his senior year. Putting Livingston in the top ten of the D-backs pitching prospects isn’t that crazy, considering he’s a 6’4 projectable RHP with quick, intriguing arm action, who hit 97.5 MPH at the 2025 draft combine. In terms of pitch selection, Livingston has an already above average two-seam and four seam fastball, along with a low 80s slider that is coming along, and a high 70s curve that needs work. The potential is there, and I would not be surprised in the slightest to see him rocket up the prospects rankings.

Yilber Diaz is a player you’ll find on a lot of top prospect lists as well, but he’s left off of my list for a few reasons. Yes, his triple digit velocity and overall stuff is very impressive, giving him some of the highest ceilings of any pitcher in the system, but the inability to consistently command his pitches and lack of control has kept from having success in MLB. This is a player who made his pro debut two seasons ago, yet still has his rookie status intact. Currently assigned to Reno, he’s off to a fantastic start in his first 11 ⅔ innings pitched in 2026; Just one earned run allowed on four hits, four walks, and a hit by pitch, with eighteen strikeouts. His 0.77 ERA isn’t too far off from his 2.04 FIP and 2.62 xFIP, though that is a super small sample size and things can change very quickly once the weather warms up in the hitter friendly Pacific Coast League.

Christian Mena made his Major League debut in 2024 for approximately one start before being waylaid with a right forearm strain for the rest of the season. Last year, Mena was again affected by an injury, this time a right shoulder strain that limited him to just nine starts in Triple-A (44 2/3 innings) and three relief appearances in the bigs. He didn’t pitch in a game after June 6. over the offseason, fellow Snakepit author Makakilo did an excellent writeup on Mena’s 2025 season that I’d recommend reading. Mena is still very young, just 23, younger than some of the pitchers who I will rank. If he was healthy currently, I’d consider ranking him near the top of the pitching prospects in the system, however, Mena hasn’t appeared in a game at all in 2026 and there’s no word of when he’ll begin his season.

Brian Curley is another from the 2025 draft that I refuse to put in my rankings yet, but unlike the aforementioned Forbes and Livingston, he has actually made his pro debut and pitched this season. A third round pick out of the University of Georgia, Curley began his season as the closer but was the Bulldog’s staff ace by the end of his season. Fellow SnakePit author Preston Salisbury has Curley as his number one pitcher in the system, when I had forgotten about him completely since the draft.

Next week we’ll look at our traditional fringey dark horse honorable mentions and begin ranking the rest of their pitching prospects.