Diamondbacks' Elite Depth Extends Deep Into the Minor Leagues

The Arizona Diamondbacks have one of the best pitching rotations in the major leagues. The top end of the club's rotation features Corbin Burnes, Zac Gallen, and Merrill Kelly, but it is the depth that makes it truly special.

Behind the top three, there are a minimum of 4 more major league caliber starting pitchers which could easily be a part of the D-backs rotation. Brandon Pfaadt, Eduardo Rodriguez, Ryne Nelson, and Jordan Montgomery each spent time with the team in 2024, and could see significant innings in 2025.

Of course not all of these arms will be part of the opening day rotation, with manager Torey Lovullo making it clear that a 6 man rotation is not in the cards at the moment.

Diamondbacks ON SI projects that if Jordan Montgomery remains on the active roster until opening day that he will remain in the rotation as the #5, leaving one of Brandon Pfaadt or Ryne Nelson in Reno, while the other stays up as a long reliever.

While it is a testament to the MLB team's pitching strength, it also compliments the organization's depth across the board. For as good as Arizona's pitching may be, their minor league system may be the best, and most experienced in all of baseball.

Projecting the Reno Aces Rotation

The Reno Aces aren't generally looked at as the cream of the crop when it comes to pitching talents in minor league baseball. The hitter friendly confines of Greater Nevada Field inflate pitchers' ERAs and generally make for a worse atmosphere when it comes to pitching.

When you look at the talent and experience of the upcoming roster, however, there is an argument that it is the single best staff in baseball.

Brandon Pfaadt or Ryne Nelson

As mentioned above, there is a high likelihood that one of these young and talented arms will wind up pitching in Reno to begin 2025. This is a shame, not only because of the talent, but because each has done a lot to earn their major league spot.

Pfaadt led the Diamondbacks in innings pitched in 2024 after the majority of the staff missed time on the injured list, or generally underperformed. This came directly after an incredibly dominant postseason stretch from the young right-hander which has earned him a big game reputation.

Nelson on the other hand may make a better case for a long reliever role with his electric stuff. His fastball has high 90's potential, and a wide array of secondaries help him keep hitters off balance.

It wasn't long ago when the 27-year-old faced significant struggles at a big league level, but a breakout second half saw him reach new heights. During the second half (beginning on July 2), the right-hander pitched to a 3.05 ERA, allowing only a .220 batting average against across 82.2 IP.

The Diamondbacks now face a reality where either the pitcher who led their staff in innings pitched the prior season, or their best starter during the second half will likely be relegated to the minor leagues.

Yilber Diaz

A lock for the Aces' rotation is top pitching prospect Yilber Diaz. His debut in 2024 went well, showcasing his stuff at a big-league level before stumbling against some tough competition. In 28.1 IP with the Diamondbacks, most of which he recorded as a starter, Diaz collected a 3.81 ERA.

In the minor leagues, the 24-year-old pitched to a 3.22 ERA in just over 50 innings with Reno, excelling even in an unfriendly pitching environment.

With major league experience now under his belt and a dominant three-pitch repertoire featuring a near triple-digit fastball, a dominant slider, and a curveball mix, Diaz will look to build upon his successful season.

Cristian Mena

Originally acquired from the Chicago White Sox, Cristian Mena has continued to blossom into a dominant pitching prospect. At only 22 years old, he has already pitched in the majors, and has paved himself an exciting route to the big leagues in his near future.

In 95.2 innings with the Aces in 2024 Mena dominated hitters, striking out 102. Over that span he pitched to a 4.61 ERA, a respectable line in the thin air of the Nevada desert.

He will once again pitch for Reno in 2025, but with more of a chip on his shoulder. A rough big league debut against the Dodgers will serve only as motivation to make his way back to the show, and to perform better once he gets there.

Tommy Henry and Blake Walston

In a similar boat are left-handed starters Tommy Henry and Blake Walston. The two young arms have each seen some big league action, with Henry pitching in 174.1 big league innings, and Walston seeing a considerably lesser amount with only 18.1 under his belt.

Still, each of them have worked as effective depth, and have proved themselves as usefull assets. Each of the two plays an important role for the D-backs, and will be a call-up candidate in part due to their southpaw stuatus.

While Henry boasts only a 5.11 ERA across his major league career, it is his ability to post and give depth when he's called on that matters.

Walston is four years younger, and has a stronger arsenal, but likely fits in a similar position. While they may not be candidates to join an opening day rotation, they will be relied upon in some key moments when the D-backs need them most.

The Amarillo Sod Poodles

Yes, the Diamondbacks' depth extends even beyond the Triple-A level. While these arms may not have the same major league experience, some names in Double A have already made themselves known, and will be knocking on the big league door as soon as next year.

Joe Elbis

Elbis, recently sent down to the Sod Poodles by the Diamondbacks, was added to the club's 40-man roster this winter. Partially this was due to his eligibility for the Rule 5 draft, but it also shows a readiness to call him up.

The righty enjoyed a strong season in 2024, earning many pitching accolades and even winning NWL Pitcher of the Month in May. At only 22 he will be a name to monitor, even while he isn't directly on the cusp of the big leagues quite yet.

Yu-Min Lin

Lin could easily be a candidate to pitch with the Aces. Diamondbacks ON SI has the left-hander out of Taiwan as Arizona's 9th best prospect, ahead of familiar names like Adrian Del Castillo, and just behind Yilber Diaz.

While he would likely be creeping up towards the major leagues by now, Lin suffered a devastating freak accident during 2024. He was struck by a line drive foul ball while standing in the dugout, an accident that changed his whole season's trajectory.

Now recovered, the highly anticipated prospect will make his case in 2025, and could still make a push for the 2026 season. Whether he winds up in Reno by opening day is yet to be seen, but considering the Triple-A depth, he may be forced to start the year with the Sod Poodles.

Dylan Ray

Similarly to Lin, Dylan Ray is one of Arizona's top pitching prospects who could very well be with the Aces by now. The 23-year-old out of Alabama was ranked by Diamondbacks ON SI as the club's 15th best prospect.

In 73.1 IP in 2024 Ray pitched to a 5.03 ERA, but has shown some strikeout ability. At 6-foot-3 the right-hander has raw potential that makes him an interesting arm to dream on, and his situation behind so many experienced arms gives him room, and time, to grow.

Summary

The Diamondbacks are in a unique situation of having more starting pitching talent than they can handle. In many ways this is a positive situation to be in, and one that they will both need, and can use in trade value.

Across multiple minor league levels they find themselves with strong potential, and importantly, big league experience that will make for an exciting future.

We will continue to monitor and cover the team's rotation battle, and will report when decisions begin to be made as opening day approaches quickly. For more news, breakdowns, and in-depth analysis stay locked in to all things Arizona Diamondbacks ON SI.