Arizona Diamondbacks' Christian Montes de Oca is set to undergo lower back surgery, a procedure that could keep the rookie reliever out for the season. Dealing with elbow inflammation, he had just made his big league debut this season. Meanwhile, Tommy Henry joins the ranks of injured pitchers for the Diamondbacks, landing on the Triple-A Reno injured list due to left elbow tightness. The struggling Diamondbacks face the San Diego Padres soon, with Zac Gallen looking to improve his recent performances against a strong Padres lineup led by Ryan Bergert, who's coming off impressive outings. Gallen's inconsistency has raised concerns, but he has historically performed well against San Diego. The Diamondbacks are facing mounting injuries affecting their pitching depth, making the upcoming matchups critical.