2025 Arizona Diamondbacks Dynasty Sleepers, Breakouts, and Busts

With dynasty season ramping up, I figured it was time to talk about some sleepers, breakouts, and busts for each team. You can find my rankings and reports to see how I value players for your dynasty leagues, but I also feel like it’s helpful to truly identify whether I believe a player can be a breakout or not. Here is where I call my shots on players I think require a call to action in dynasty, whether it be to buy or sell that player.

While you are here, be sure to check out the Arizona Diamondbacks’ top prospect list. It is nearly 10k words covering everything you need to know about the Arizona Diamondbacks farm system and it now has reports on their top international signees from January 2025.

The Arizona Diamondbacks Sleeper, Breakout, and Bust article is just below, and it is a free read for everyone! Enjoy!

Arizona Diamondbacks Dynasty Sleepers, Breakouts, Busts

MLB Sleeper: Brandon Pfaadt, RHP, 26, 6’4”/220

Pfaadt put together a strong 2024 season that the surface stats don’t reflect. Across 181.2 innings in his first full MLB season, Pfaadt posted a 4.71 ERA and struck out just 24.3 percent of hitters. He did show impressive control, walking just 5.5 percent, and Pfaadt posted a FIP, xFIP, and SIERA, all 3.65 or lower.

It seemed that Pfaadt just lost steam to end the year. Through July 21, Pfaadt had a 3.74 ERA. Over his final 61.1 innings, a 6.60 ERA. While it was a rough end to the season, Pfaadt still posted three starts with at least ten strikeouts over his final nine. His ERA over that span was largely skewed by two blow-up starts in which he allowed eight runs.

One major issue was the 13 home runs that he allowed on his sweeper. When the pitch was on, it played well as it generated a 36 percent whiff rate. But when he missed over the heart of the plate, the pitch was hammered.

When his performance was bad, Pfaadt appeared to be toying with his pitch mix. It is also worth noting in some of his dominant starts down the stretch; Pfaadt used the curveball more, which was highly effective.

If Pfaadt curbs the home run problem a bit, he could turn into a mid-threes ERA type arm quickly.

MLB Breakout: Gabriel Moreno, C, 25, 5’11”/195

You might be inclined to think that, at this point, Moreno is just who he is. But it is also important to remember that with catchers, development is much slower. Entering his age-25 season, there are plenty of reasons to like what Moreno brings to the table.

Lower body injuries limited Moreno to just 351 plate appearances in 2024, when he slashed .266/.353/.380 with just five home runs. The underlying data is what catches my eye though. We are looking at a steady increase in barrel rate over the last few seasons, up to 6.6 percent in 2024. Moreno also set a new career-high max exit velocity of 111.1 mph, and his sweet spot rate increased.

Moreno saw a nice drop in his ground ball rate and was below 50 percent for the first time in his career. From a plate discipline standpoint, Moreno saw his chase rate drop to an impressive 21 percent, down from 26, and he made contact on 82 percent of swings.

Not only is Moreno valuable behind the plate, but the bat could break out in 2025 with just a little more loft in the swing. With 500 plate appearances, Moreno could reach 12 or more home runs, and it will likely come with a strong batting average. Buy Moreno in 2025.

MLB Bust: Justin Martinez, RP, 23, 6’3”/180

There is no denying that Justin Martinez is electric. Throwing a 100 mph fastball with a devastating splitter and slider is a good recipe for success. In fact, the splitter generated whiffs at a 54 percent mark and the slider at 45 percent in 2024. This helped lead to a 29.5 percent strikeout rate and a 2.48 ERA.

So what is the issue then? Martinez is being drafted to be the closer, going near pick 200. That’s all fine and dandy if the Diamondbacks did not seem intent on having AJ Puk close games for them. Martinez also struggles to throw strikes at times, which led to a 12 percent walk rate.

The finish to 2024 for Martinez was also frustrating, as he posted a 4.50 ERA with a 1.67 WHIP. If the Diamondbacks gave him the vote of confidence as the Diamondbacks closer, we would not be talking about him here. The stuff is good and will play despite the command.

While Martinez won’t be a complete bust, he probably is not going to get the bulk share of saves you are hoping he will get.

Diamondbacks Prospect Sleeper: Jose Cabrera, RHP, 22, 6’3”/190, A+

After missing the first half of the 2024 season after receiving an 80-game suspension for testing positive for Boldenone, Cabrera came back with a vengeance. He showed major improvements throughout the year as he worked his way back and found his grove as a starter.

After a rough first few outings of 2024, Cabrera finished his final seven starts, completing 47 innings with a 1.15 ERA and 47 strikeouts to just ten walks. Over that span, Cabrera posted an 18 percent swinging strike rate while throwing strikes at a 66 percent rate.

His fastball works in the mid-90s, reaching 97, and a lot of the success can be attributed to a new cutter that changed the dynamic of his arsenal completely. He throws a fading changeup to lefties and will throw two variations of a breaking ball that sometimes morph. But Cabrera does have a deep arsenal, and while I don’t love mechanical operation, I am curious to see if this continues to work at higher levels.

Diamondbacks Prospect Breakout: JD Dix, SS, 19, 6’2”/180

Wisconsin prep bats don’t always get a ton of love, but that changed this year with Dix, as the Diamondbacks selected him as the 35th overall pick. Dix is a physically gifted shortstop standing at 6’2”/180 that oozes projection. Having a high waist and an explosive lower half, Dix generates power with ease from both sides of the plate. He looks natural from both sides of the plate and generates a ton of bat speed from both.

A natural athlete, Dix has posted strong run times at events, with his best 60-yard dash at 6.48 seconds. Dix lifts the ball with ease, hitting a ton of line drives and fly balls to the outfield gaps. With the projection on the frame, there is plenty of power upside to dream in the long term with the quality athlete that he is.

Dix did miss time with a torn labrum during his senior year, but reports say that the shoulder is good to go, and he should be fully healthy.