The Arizona Diamondbacks are adding to their starting pitching depth, as evidenced by one of their most recent roster additions.

The Diamondbacks are thin when it comes to rotation depth. Outside of their five healthy major league starters, there are few options in the minor leagues that stand out.

The harsh reality is no team manages to make its way through a 162-game season without dipping into that depth in some manner. Arizona has had to do so in each of the past several seasons to a high degree.

But according to one of Arizona's recent transactions, they're bringing in a former Chicago Cubs pitching prospect to provide just that kind of Triple-A depth.

Diamondbacks sign Kohl Franklin to minor league deal

Arizona has signed right-handed starting pitcher Kohl Franklin to a minor league contract. Franklin was the Cubs' No. 6 prospect in 2021 and sat at No. 26 as recently as 2023. He's struggled to stay on the field, however.

Franklin was drafted in 2018, taken with pick No. 188 in the sixth round of the 2018 MLB Draft out of Broken Arrow High School in Oklahoma.

Franklin is now 27 years old, after spending parts of seven seasons moving up and down the Cubs' minor league farm system. He did not pitch in 2021 due to an oblique injury and subsequently missed most of 2024 and 2025 after undergoing elbow surgery.

As a result, Franklin has only pitched a total of 277.2 professional innings, and never more than 105 in a season, which happened in 2023.

He tossed 44.2 innings in the 2026 season as he worked his way back to full strength. 30.1 of those inning came in eight appearances (seven starts) for the Triple-A Iowa Cubs, for whom he produced a 4.15 ERA, 26 strikeouts and 15 walks.

Due to the small sample size and lack of recent heavy workload, it's hard to evaluate exactly what the Diamondbacks might be getting out of Franklin this year.

Franklin's fastball sat in the 92-93 MPH range for the most part at the end of 2026, though it did climb as high as 95 MPH in his final game of the season. He also throws a changeup, curveball and cutter that mostly mirrors his four-seam.

In theory, he could provide much-needed rotation depth for the Reno Aces, however the offense-heavy Pacific Coast League has inflated many a pitcher's ERA.

Arizona's rotation is already thin at the major league level, and they may be forced to turn to one of Kohl Drake, Mitch Bratt or Jose Cabrera again. Franklin may be in the mix there, as well, or could be a long-relief option should the Diamondbacks need that type of coverage.