Introduction
Continuing with the deep dive into the more interesting Diamondbacks pitching prospects, we’ll be looking at two sets of very different pitchers.
More RHP Prospects
Junior Ciprian ( FG | B-Ref | Pipeline )
Bats/Throws: R/R Height/Weight: 6’3″, 180 LBs Born:: 6/02/2005 in Santo Domingo Centro, Dominican Republic
Scouting Grades: Fastball: 60 | Curveball: 55 | Slider: 50 Control: 50
Background: The Diamondbacks signed Junior Ciprian out of the Dominican Republic in August of 2023, for a signing bonus of only $20,000. Ciprian was older than the norm for prospects
out of the Dominican Republic, only signing a few months after his 18th birthday, and then he didn’t break into stateside ball until 2025. Long story short, his development is probably further behind than where you’d expect a pitcher of his age and background to be.
Ciprian’s time in the Dominican Summer League consisted of just 3.0 innings in 2023 and 25 innings in 2024, so we’re gonna jump ahead to 2025. Ciprian started out the year in the Arizona Complex league, where he’d pitch 39 innings with a 4.62 era, along with a rather ugly 6.14 FIP and 5.82 xFIP. The ERA was slightly above league average with a 94 ERA-, and as expected, a well below average 121 FIP. He’d then get promoted to Single A Visalia, where he’d appear in 5 more games, 15⅔ innings total, with a 3.45 ERA, 3.62 FIP, 4.73 xFIP.
Ciprian would return to Visalia to start the 2026 season, and he’d out up 71⅔ innings pitched with a 2.76 ERA, 4.61 FIP, 5.19 xFIP. 51 ERA- and 83 FIP-. That would earn Ciprian a promotion to High-A Hillsboro, and he’d pitch 32⅔ innings with a 4.68 ERA, 4.40 FIP, 5.65 xFIP, 95 ERA-, and 90 FIP-.
Scouting report:
Junior Ciprian is essentially the ideal ’projectability’ type of pitching prospect, who seems to be becoming that pitcher he was projected to be. Ciprian already sports an mighty impressive fastball, that can touch 98-99 AND has 18 inches of vertical break, giving him a plus primary pitch, that is complimented by a high 80s slider with late dive and break. He lacks a true plus third pitch though to go after left-handed batters, so he’s going to need to develop those tertiary pitches to succeed as a starting pitcher at the MLB level. That said, I have very little doubt that he could succeed as a reliever though with just the main two pitches.
Wellington Aracena RHP ( FG| B-Ref |Pipeline )
Bats/Throws: R/R Height/Weight: 6’3″/ 180lbs Born: 12/27/2004 in Mao, Dominican Republic
Scouting grades: Fastball: 65 | Curveball: 40 | Slider: 50 | Cutter: 55 | Changeup: 40 | Control: 40
Background: The Mets signed him out of the Dominican Republic for just $70,000 as part of their 2022 international draft class. He’d eventually broke out as a prospect in 2025, but was acquired by Baltimore in the Gregory Soto trade at the deadline. The Diamondbacks acquired Aracena in the Blaze Alexander trade back in Jamuary.. Aracena was assigned to High A Hillsboro, whwre he pitched in 19 games, started 16 of them, putting up a 4.83 ERA, a 98 ERA-, 4.09 FIP, 4.55 xFIP and an 84 FIP- in 72⅓ innings. Double A Amarillo and the Texas league didn’t treat him nearly as well in the six games he appeared in he put up a 6.91 ERA, 117 ERA, 5.71 FIP, 5.04 xFIP, and a 102 FIP- in 27⅓ innings pitched.
The biggest issue at both levels has been a high walk rate and poor command at times, with Aracena walking 13.1 percent of batters faced in High-A and 12.7% of batters in Double-A.
Scouting Report: Aracena just might have the best raw stuff of any of the pitchers discussed today; He usually sits in the mid to high 90s with his four-seam fastball, but has topped out at 100+ mph. His low 90s cutter has impressive glove side run that I’d call it a fully developed pitch. His slider generates a lot of swings and misses, with a near 50% whiff rate. He apparently throws a two-seamer and a changeup as well, but they’re used so little they’re a non factor.
Unfortunately, Aracena’s command might be the worst of the four pitchers here, and overall he’s very inconsistent from game to game. He might look unhittable one outing and then the next he can’t find the strike zone. I honestly question giving him an average grade for Control, but on a good day, he does command the strike zone well
Junior Sanchez (FG | B-Ref | Pipeline )
Bats/Throws: R/R Height/Weight: 5’10” 175lb Born: 9/16/2005 in Santo Domingo, Dominican Republic
Scouting grades: Fastball: 40 | Slider: 55 | Changeup: 50| Cutter: 50 | Control: 50
Background: Junior Sanchez signed with the D-backs for $50,000 as a 17-year-old out of the Dominican Republic in January 2023. He’d make his pro debut in the Dominican Summer League the same year and putting up a 2.76 ERA, a 3.84 FIP, and a 4.44 xFIP in 42 ⅓ IP spread across 11 games. Looking at his above average 59 ERA- and 82 FIP- shows just how good he was, especially as a 17 year old and one of the youngest pitchers in the league. Sanchez came stateside and pitched in the Arizona Complex League for all of the 2024 season. He’d pitch 33 ⅓ innings across 13 games with a 3.78 ERA, 4.88 FIP and 4.89 xFIP. 72 ERA- and 91 FIP-.
In 2025, Sanchez would start the year in Single-A Visalia, and in 73⅔ innings he’d put up a 2.32 ERA, 3.95 FIP, 4.19 xFIP, 52 ERA- and an 87 FIP-. He’d then get promoted to Hillsboro. put up 2.40 ERA in 105 innings between Single-A Visalia and High-A Hillsboro, which was the best among D-backs Minor Leaguers (min. 100 IP) and ranked 10th among MiLB hurlers who met that requirement. This year Sanchez return to High A Hillsboro, where pitched in nine games, six as a starter, totalling 41⅓ innings with a 2.61 ERA, 53 Era-, 3.07 FIP, 4.46 xFIP, and a 63 FIP. He struck out 35% of batters he faced, while walking just 6.3%.
If you look at just his 89 ERA- and 98 FIP- for the 72⅓ innings he pitched in AA Amarillo, you’d be forgiven for assuming he didn’t also have an ERA over five. This is the Texas league and a 5.23 ERA, 5.50 FIP, and 4.89 xFIP are above average. His strikeout rate shrunk down 23.8% and his walk rate jumped up to 10.3%.
Scouting Report: At 5-foot-10, Junior Sanchez is an undersized righthander with very little remaining projection in his frame. His delivery is very deceptive, with a short arm action and vertical release, and he hides the ball very well. His average fastball velocity is up, more than the initial scouting reports I came across, but it still only tops out at 94-95 mph on his best day. He an excellent feel for all of his secondary pitches, with the best of them being a high-spin sweeper in the mid 80s. He has advanced feel for it and the pitch results in high chase and whiff rates. Sanchez also has a high-80s cutter and changeup. His changeup has good action and can miss bats, while his cutter is a pitch he can comfortably land in the zone.
Sanchez succeeds in spite of the lack of raw velocity, but the amount of movement he has on all four of his pitches and the command he has over all of them seems to make up for that, at least so far in the minor leagues. The real question is will his arsenal of pitches be enough for him to find success at the MLB level in today’s game, facing batters with better pitch recognition. The drop in strikeout rate and surge in walk rate tells me that he’s might have a hard time repeating his previous success as he faces tougher hitters going forward.
Sanchez has the intelligence, personality and makeup to succeed in spite of the limits on his stuff though, and I wouldn’t bet against him finding success eventually.
Mason Marriot ( FG | B-Ref | Pipeline)
Bats/Throws: L/R Height/Weight: 6’0 /198 lbs Born: 8/14/2002 in Tomball, TX
Scouting grades: Fastball: 50 | Curveball: 60+ | Slider: 50 | Changeup: 45 | Control: 50
Background: As a freshman at Baylor, Mason Marriot was deployed out of the bullpen, but shifted to the starting rotation for his sophomore and junior seasons. Marriot was far from successful though, putting up an awful 7.52 ERA and 6.28 FIP in 58⅔ IP his sophomore season, followed by a slightly-better-but-still-awful 5.94 ERA and 5.09 FIP in 69⅔ IP his junior season. In spite of that, the D’Backs liked him enough to draft Marriot in the 6th round of the 2024 draft, although they signed him for below slot at $241,000.
Marriot got off to a great start to begin his pro career, giving up just a pair of runs on six hits and walk(while striking out 6), in the seven innings he pitched in 2024. (Obviously a small sample size; that works out to a 2.34 ERA, 54 ERA-, 2.78 FIP, 3.84 xFIP, 58 FIP-)
In 2025, he was assigned to high-A Hillsboro, where he continued that hot start in his first four games, giving up just five runs on 13 hits and eight walks, while striking out 25 batters in 19⅔ innings . That works out to a 2.29 ERA, 51 ERA-, 2.13 FIP, 2.91 xFIP, and a 48 FIP-. Unfortunately, after those four games, Marriot suffered a season ending UCL injury, necessitating Tommy John surgery and he wouldn’t pitch again until the middle of 2026 season.
I’ll be blunt, Marriot had some ugly numbers in his three game rehab stint and then predictably struggled after he was promoted to AA Amarillo, but in the six games he pitched in A+ Hillsboro he was very impressive and looked like the pitcher he was prior to the injury. If you look at his just Hillsboro he had a 3.29 ERA with a 1.60 FIP and 2.28 xFIP. In the relatively pitching friendly Northwest League, that results in a still well above average 67 ERA- and very impressive 33 ERA-. If you add in the other two leagues, it adds up to a 5.52 ERA, 96 ERA- along with a 4.87 FIP and an 87 FIP-.
Regardless, the stat that stands out to me the most is his high rate of strikeouts (K/9, SO%) along with relatively low walk rates. In high-a Hillsboro he struck out 37.3% of batters he faced while walking only 5.9% of batters. In AA Amarillo he struck out 25% percent of batters for a 11.37 K/9
I am not really sure if the D-backs intend on keeping Marriott as a starter, and to be honest, considering how limited his innings have been, does he actually qualify as one? He has technically started 15 out of the 19 games he’s played in, but has only pitched 51⅔ innings. While Marriott doesn’t have blow me away velocity, he has the arsenal of pitches to work as a starter.
Looking at Marriott’s pitch mix, he shows a natural feel for spin and the ability to command his breaking balls with big movement profiles. Marriott’s fastball is a generic-looking four-seamer that sits in the 94-96 mph, but it is a very hittable pitch. He’s going to need to find a better shape for his fastball if wants to continue finding success as he moves up the ladder of professional baseball.
As far as his secondary pitches go, he has three above-average pitches. The best in the trio of secondaries is a low 80s curveball with a 2700+ RPM spin rate and a heavy two-plane break Marriott also mixes in a mid-80s sweeper and a high-80s changeup, but they’re used much less frequently, although latter is an excellent pitch for keeping the ball on the ground.
Based on watching a couple of his outings and looking at his career fielding statistics he’s a competent above average fielder on the mound.
Conclusions
Of the four pitchers, Junior Ciprian might be one of the safer bets if he continues to develop like he has. Aracena has great stuff and will eventually find success if he can be a little more consistent hitting the strikezone. Junior Sanchez lacks the raw stuff but has everything else. Finally, Mason Marriott is gonna need to be stretched out as a starter; but he has the stuff to he successful as reliever.
Next time we’ll look at the final handful of pitching prospects that have shown potential, but didn’t make the cut here for whatever reason.
