JUNE 17: As expected, Arizona reinstated Gallen from the IL this morning. Righty Humberto Castellanos was optioned to Triple-A Reno in a corresponding move.
JUNE 16: The Diamondbacks announced they’re planning to activate Zac Gallen from the injured list. He’ll start tomorrow afternoon’s game in San Francisco, his first MLB action in nearly six weeks.
Gallen went on the IL in mid-May with an ominous-sounding diagnosis: a minor sprain of the UCL in his throwing elbow. He wound missing a fairly notable amount of time, but the D-Backs are surely relieved it didn’t require any sort of surgical repair. Gallen looks like a potential cornerstone rotation piece for Arizona. Since the D-Backs acquired him from the Marlins for Jazz Chisholm Jr. at the 2019 trade deadline, he’s tossed 142 1/3 innings of 2.85 ERA/3.54 FIP ball with a strong 28.4% strikeout rate.
The 25-year-old has been limited to five starts this year, and the D-Backs have certainly felt his absence. Arizona starters have pitched to a disastrous 5.55 ERA, the second-worst mark in the league (the Pirates are at 5.57). Diamondbacks starters also rank near the bottom of the league in strikeout rate (20.4%), strikeout/walk rate differential (11.9 percentage points) and SIERA (4.55).