Key Diamondbacks Prospects Eligible for Next Rule 5 Draft

The Rule 5 Draft is coming up in December, but it's never too early to take a look at eligible prospects. Players become eligible to be selected if they spend five seasons in the organization if they sign at 18 or younger, and four seasons if they sign at 19 or older. If their team fails to add them to their 40-man roster, other teams can select them to their 40-man roster in the offseason.

The Diamondbacks will have to make some tough roster decisions in November on these players. Here's a list of prospects who are eligible for the draft, ordered by the likelihood Arizona will add them to their 40-man roster.

No-Brainer Decisions

LHP Yu-Min Lin's season got off to a late start, but he's performed well so far in Reno. In four starts, spanning 21.2 innings, he's pitched to a 3.74 ERA. There are some concerns about his peripherals, as he's allowed five home runs, walked 12, and struck out 18. That will be an area of improvement as he gets more starts in Reno, otherwise, it could catch up to his bottom-line results.

RHP Dylan Ray has put together four consecutive Quality Starts. In that stretch, he's allowed just five runs in 24 innings with 29 strikeouts and only two walks. Thanks to some mechanical adjustments, the right-hander is seeing his fastball velocity hit 94-95 MPH more often, per Steve Gilbert's newsletter. For his season numbers, he's down to a solid 4.15 ERA and a 47/16 strikeout-to-walk ratio in 43.1 innings.

LHP Spencer Giesting is putting together another solid season with Double-A Amarillo. Giesting has a 3.38 ERA with 54 strikeouts and 18 walks. Despite pitching in the tougher environment of Hodgetown for his home games, his 2025 numbers are reminiscent of his 2023 numbers. His slider has been a big swing-and-miss pitch for him so far this season.

Possible Candidates Due to 2025 Performance

LHP Kyle Backhus was not selected last winter despite being left out there. The sidearming left-hander has a 2.29 ERA in 19.2 innings, with solid strikeout (31.5%) and walk (9.0%) rates. While opposing hitters are batting .280 against him, he's limited the number of extra-base hits. 15 of the 21 hits allowed have been singles. Due to the uptick in strikeout rate, he's making himself a midseason call-up candidate and might not have to sweat things out in November.

Unlikely to be Added Barring Significant Improvement

RHP Landon Sims was a former bullpen ace at Mississippi State, but his stuff hasn't recovered after rehabbing from Tommy John surgery. He has a 5.29 ERA in 16 appearances, although it can be deceiving as he's allowed just one run since April 27. However, the downside has been too many walks, with 13 strikeouts to 10 walks in his last 9.2 innings. Reducing the walk rate will be critical for him to be considered for a 40-man spot.

INF Jose Fernandez has made steady progress in the system, slashing .295/.353/.424 with Double-A Amarillo and serving as the utility infielder. He's still fairly young for the level and his 103 wRC+ suggests he's holding his own. Given the glut of infielders in the upper level of the minors and the upside of a backup infielder, it's a good chance the Diamondbacks leave him unprotected.

1B Ivan Melendez is hitting .193 with seven home runs and a .744 OPS on the season. He has stalled in Double-A due to his inability to control his strikeout rate. In each of the last three seasons, he's posted a strikeout rate well above 30%. That is a disqualifying red flag for a prospect with as much raw power as he boasts.

RHP Alfred Morillo finds himself in a similar position as Sims. He's pitched to a 4.20 ERA so far in 14 appearances, with four saves, but digging deeper unearths some very troubling results. Going up to Double-A, his strikeout rate has plummeted from 29% to 19% while his walk rate has stayed relatively the same, up from 13% to 15%. Like Sims, he'll need to work on drastically reducing the walk rate before getting considered for a 40-man spot.