Diamondbacks Sign Casey Kelly To Minor League Deal

The Diamondbacks have signed right-hander Casey Kelly to a minor league deal, according to the transactions log on Kelly’s MLB.com profile page.

Kelly, 35, was a first-round pick by the Red Sox back in 2008. He quickly rose to minor league stardom, becoming a consensus top-100 prospect in the sport before he was traded to the Padres alongside future All-Star Anthony Rizzo in exchange for Adrian Gonzalez. Kelly made his big league debut with San Diego just a year later, though he struggled to a 6.21 ERA in 29 innings of work across six starts in that first big league cup of coffee. Tommy John surgery in 2013 forced him to stay away from the big league mound for quite some time after that, however, and upon his return in 2015 he was torched to the tune of a 7.94 ERA in 11 1/3 innings of work that brought the Padres chapter of his career to a disappointing end.

Kelly bounced through the Braves, Cubs, and Giants organizations over the next couple of seasons, even getting a brief look in the majors with Atlanta during the 2016 season, but it wasn’t until the 2018 campaign in San Francisco that the right-hander found success in the majors. That success was fairly limited, as Kelly pitched just 23 2/3 frames at the highest level that year, but his 3.04 ERA was the first above-average showing in the majors of his career. It even earned him some attention on the other side of the world, as Kelly went on to depart the Giants organization in favor of joining the Korea Baseball Organization’s LG Twins.

Kelly’s stint in Korea ultimately lasted six seasons, and saw him put together an impressive overseas career. The right-hander pitched to a 3.25 ERA overall in 989 1/3 innings of work for the LG Twins in parts of six seasons from 2019 to 2024. Those first four seasons were particularly impressive, as Kelly made at least 27 starts in each of them with ERAs ranging from 2.54 to 3.32 and solid peripheral numbers to match. Unfortunately, Kelly started to show signs of decline in 2023 that brought about the end of his KBO career in 2024 after he struggled to a 4.51 ERA in 19 starts for the LG Twins that led the club to cut him from the team in July of last year.

After being cut loose in Korea, Kelly made his way back into stateside ball with the Reds on a minor league deal. He managed to get called up to the majors for a brief stint down the stretch last year, his first stint in the majors in more than half a decade. He pitched just 5 1/3 innings for the Reds last year, surrendering three runs on three hits (one homer) and a walk while striking out four. The right-hander was then outrighted to Triple-A Louisville in August and elected minor league free agency back in October. Now, Kelly appears likely to serve as non-roster depth for the Diamondbacks headed into 2025. He’s got plenty of competition on the club’s pitching depth chart, with Jordan Montgomery, Ryne Nelson, and Tommy Henry among the pitchers just on the 40-man roster who could vie for a long relief role with the club this season.