Diamondbacks Outright Humberto Castellanos

The Diamondbacks have assigned right-hander Humberto Castellanos outright to Triple-A Reno, according to the transactions log on his MLB.com profile page. Castellanos was designated for assignment by the club last week to clear roster space for the return of right-hander Merrill Kelly.

Castellanos, 26, made his big league debut with the Astros back in 2020 but struggled in 10 2/3 innings of work during the shortened season with a 6.75 ERA and 5.35 FIP. Despite those struggles, the Dbacks were interested enough in the righty to claim him off waivers from Houston the following winter, and while the 23-year-old didn’t make the club’s Opening Day roster in 2021 he found his way to Arizona later that season in a swing role. He’d remain in that flexible role with the club over the next two years, shuttling not only between the major and minor leagues but also between the bullpen and the rotation.

Overall, Castellanos’s results left much to be desired in 2021 and ’22 as he pitched to a combined 5.30 ERA and 4.91 FIP in 90 innings of work. It’s worth noting, however, that the right-hander’s numbers were much better out of the bullpen as he posted a 3.68 ERA while striking out 22.2% of batters faced. That may have portended the ability to act as a solid pure reliever, although any hope of finding out more about that possibility was temporarily scuttled by Castellanos undergoing Tommy John surgery late in the 2022 season. Castellanos was outrighted off the club’s 40-man roster while rehabbing but returned to the club on a minor league deal.

The right-hander returned to action as a starter at the minor league level earlier this year but was brought up to the majors to act as a multi-inning reliever when he eventually got the call back to the bigs in June. That first taste of big league action in nearly two years did not go well, as he was lit up for five runs in 2 1/3 innings of work before promptly being sent back down to the minors. He returned to the big leagues last month and looked a lot better as he scattered just six hits and two walks across eight innings of work split between six relief appearances (good for a 1.13 ERA and 2.80 FIP), but that small-sample success wasn’t enough to convince Arizona to keep him on their 40-man roster, perhaps due in part to his lackluster 18.2% strikeout rate even in that otherwise-impressive stretch.

Now back in the minors with Arizona, Castellanos figures to act as a non-roster depth option for the club down the stretch. The right-hander’s pitch counts have stayed fairly low during his most recent stint in the minor leagues and he’s seemingly benefited from that change, with a 2.08 ERA in 13 innings of work across three starts. If Castellanos continues to find success in shorter bursts at the minor league level, it’s feasible to imagine him getting another look in the majors as a reliever at some point in the future, whether that be with Arizona later this year or after he returns to free agency this winter.