The Arizona Diamondbacks did not manage to escape the brutality of the 162-game grind in the 2025 season, and it manifested in the form of a disappointing, injury-racked year.
Despite coming into 2025 with sky-high expectations, the D-backs only managed an 80-82 record, sitting out of playoff action for the second season in a row following their 2023 pennant run.
The sheer number of injuries (and some underperformance) forced the D-backs to turn to arms that fans likely would never have expected to see take the mound. One such emergency-use pitcher was veteran right-hander Casey Kelly.
Kelly did not have a substantial role, by any means. But his presence on the roster and usage was a perfect example of the D-backs’ extreme level of relief pitching need, both in 2025 and into the offseason.
As Arizona Diamondbacks On SI breaks down each individual season from the entirety of the 2025 roster, the below article will be updated with the proper links as the season reviews are published:
Related Content:Â Breaking Down Every Diamondbacks Player’s 2025 Season
Arizona Diamondbacks 2025 Player Review: Casey Kelly
Casey Kelly 2025 and career stats | Alex D’Agostino.
Kelly is a 36-year-old veteran of 12 seasons, though only parts of six of those seasons were in the major leagues. From 2019-2024, Kelly was a prolific (and extremely sucessful) starting pitcher in Korea, pitching workhorse innings for the LG Twins and delivering ERAs below 4.00 in five of six seasons.
Upon his return to MLB in the middle of the 2024 season, Kelly only managed to make two appearances (5.1 innings) for the Cincinnati Reds.
But just ahead of Spring Training, the D-backs inked Kelly to a minor league deal. He made 24 appearances (20 starts) for the Reno Aces, pitching to a 5.63 ERA over 115 innings. While a 5.63 ERA isn’t far from average in the Pacific Coast League, Kelly somehow only managed 61 strikeouts in that span.
On August 6, the D-backs called him up to the majors. He got two outs without allowing a run against the Padres that same day, then closed a game two days later against the Rockies with a scoreless ninth inning. It was not a save situation.
Kelly was optioned back to Reno, then recalled again, but never stepped on the mound in the majors for the remainder of 2025. He has since elected free agency.
Casey Kelly: 2026 Outlook
Kelly is not a candidate to return to the D-backs, unless they opt to re-sign him for minor league depth. While Kelly does provide length and he was very effective in his tiny sample size, he’s not the type of arm Arizona would need to pursue, barring another brutal bout of injury luck in 2026.
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