This story was excerpted from Steve Gilbert’s D-backs Beat newsletter. To read the full newsletter, click here. And subscribe to get it regularly in your inbox.

PHOENIX -- The D-backs were excited when they acquired right-hander Cristian Mena from the White Sox in exchange for outfielder Dominic Fletcher on Feb. 3.

The D-backs liked -- and still like -- Mena’s power stuff. And when evaluating his or any other pitcher’s performance at Triple-A Reno, you have to look beyond the ERA. In the hitter-friendly Pacific Coast League, the ball flies out of the ballpark.

“We felt like it was an opportunity to get a young starting pitcher,” D-backs GM Mike Hazen said at the time of the trade. “Once they sort of break out and get to the Major League level and play and play well, you have no chance to get them. We felt like this was an opportunity for us to add a really young starting pitcher [who has] already been to Triple-A, and we think he has really good stuff.”

Of course, at the time of the trade, the D-backs were feeling pretty good about their big league rotation. It was going to feature Zac Gallen, Merrill Kelly, Eduardo Rodriguez and Brandon Pfaadt, along with one pitcher to be chosen from a group of young arms. When they signed Jordan Montgomery to a one-year deal on March 29, it looked like they had an embarrassment of riches and that Mena (the D-backs' No. 11 prospect, according to MLB Pipeline) might spend the entire year at Reno honing his craft.

But injuries to the D-backs' rotation, including Montgomery -- who went on the 15-day injured list on Tuesday with right knee inflammation -- opened the door for Mena, who is expected to make his Major League debut on Wednesday at Dodger Stadium. And keep an eye on No. 16 prospect and Double-A Amarillo starter Yilber Diaz, who is rising in the pecking order.

Mena was a candidate to be the top performer for Reno for the first half of the season, but the selection is catcher and No. 27 prospect Adrian Del Castillo.

Del Castillo, whom the D-backs selected in the second round of the 2021 MLB Draft out of the University of Miami, has risen steadily through Arizona's farm system and is knocking at the door of the big leagues.

Del Castillo has a .329/.401/.608 slash line and has hit 30 doubles, three triples and 16 home runs in 76 games with Reno.

“He’s had a really good season for himself,” Hazen said. “Offensively, he’s smoked the ball all year, so that’s good to see. He certainly has an offensive component. At some point, if he keeps doing this and we need to make more changes, he’s going to get a look [in the big leagues]. Defensively, he’s done a good job. He needs to improve some of the throwing stuff and blocking; I think he’s done a good job receiving.”

The D-backs are set at starting catcher right now with Gabriel Moreno, but they designated for assignment veteran backup Tucker Barnhart on Tuesday and promoted Jose Herrera to the big leagues on June 22.

Double-A Amarillo: 1B Deyvison De Los Santos (D-backs' No. 14 prospect)

Yes, I’m aware that De Los Santos is with Reno, but he started the year at Amarillo and has played more games there, so he gets the nod.

De Los Santos slashed .372/.426/.696 in 38 games with the Sod Poodles, and his promotion to Triple-A on May 21 hasn’t appeared to faze him. De Los Santos has a .315/.361/.658 slash line in 37 games with Reno.

“He doesn't waste at-bats,” D-backs farm director Shaun Larkin said. “If he chases out of the zone, he's able to rebound within the at-bat and finish it off with two strikes. And when he hits it, he crushes it.”

The D-backs are fortunate to still have De Los Santos in their system. He was picked by the Guardians in the Rule 5 Draft on Dec. 6 but was returned to Arizona on March 23.

High-A Hillsboro: RHP Joe Elbis

The 21-year-old from Venezuela made 14 starts for Hillsboro last year after opening the 2023 season at Single-A Visalia. He’s continued to make strides in his development this year.

In 13 starts for the Hops, Elbis has a 1.99 ERA and has allowed just 57 hits in 77 innings.

“He's kind of under the radar, but man, he's quietly doing a great job,” Larkin said. “He's got a nice pitch mix, he moves the ball around the zone and [he] is one of those guys that limits hard contact.”

Spencer Giesting deserves a mention here as well. He compiled a 1.50 ERA in 10 starts with Hillsboro before being promoted to Amarillo on June 18.

Single-A Visalia: OF Druw Jones

Jones was selected by the D-backs with the second overall pick in the 2022 MLB Draft, and injuries have hampered him since.

This year, though, he’s been healthy. And after a slow start at the plate, he has really picked it up. Jones (D-backs' No. 3 prospect, No. 79 overall) is slashing .267/.384/.397 in 64 games. Defense has never been an issue for Jones, who is an outstanding center fielder.

“He’s only 20 years old, and he's had a good year,” Larkin said. “Especially coming off the past year, with the injuries and just all the stuff he’s dealt with with the hype and everything else. He’s just kind of settled in and had a good, quality first half, and he’s only getting better.”