Zac Gallen seeking second medical opinions as Diamondbacks return from All-Star break

Zac Gallen is seeking second medical opinions on his injury, per Yahoo Sports, and the uncertainty surrounding the Arizona Diamondbacks' rotation has deepened considerably as the club returns from the All-Star break.

What happened

The Diamondbacks' manager addressed the situation without resolution, per Arizona Sports. The evaluation is ongoing, with Gallen awaiting perspectives from additional doctors before any path forward can be determined. The club has not announced a diagnosis, a timetable, or a next step beyond the evaluation process itself.

Also per azcentral's Nick Piecoro, as relayed by Yahoo Sports, the Diamondbacks are recalling first baseman Tyler Locklear from Triple-A Reno. The two developments — one unsettling, one procedural — arrived together as Arizona opened its post-break schedule.

Why it matters

The second-opinion process is worth understanding on its own terms. When a player and a club seek additional medical perspectives, it typically means the initial evaluation left enough ambiguity that more information is needed before a path forward can be charted. It does not mean the worst outcome is coming. It does mean the worst outcome has not been set aside. That distinction matters enormously for how Arizona plans the back half of its season.

Gallen has been a central figure in the Diamondbacks' rotation. His absence — however long it turns out to be — creates a real structural question for a pitching staff navigating the demands of a long season. The club has not placed him on the injured list, has not announced a surgery, and has not provided a return window. What it has said publicly is that the evaluation is ongoing and incomplete.

Is Tommy John surgery actually on the table?

Per Arizona Sports, it is one possibility that has been raised in the context of the second-opinion process — but the outlet explicitly noted it is not a certainty, and the Diamondbacks have not announced any diagnosis. The reporting frames it as a concern worth monitoring, not a conclusion. Until the evaluation is complete and the club speaks, the honest answer is that nobody outside the medical room knows.

Arizona Sports was equally careful to note that the second-opinion process carries no guarantee of a severe outcome. The framing is appropriately cautious, and so is the desk's.

Where the club stands

Arizona returns home to Chase Field for a three-game series against the St. Louis Cardinals. On Friday, July 17, Merrill Kelly is the probable starter opposite Michael McGreevy. Brandon Pfaadt takes the ball Saturday, July 18, against Dustin May. Eduardo Rodriguez is lined up for Sunday, July 19, against Andre Pallante.

That rotation — Kelly, Pfaadt, Rodriguez — is what the Diamondbacks have available and visible right now. Gallen's name is conspicuously absent from the weekend slate, which is itself a data point, even if it is not an explanation.

The Diamondbacks are 86-76 on the season, a .531 winning percentage, and sit third in the NL West, 14 games back in the division. Per the verified standings, they have been eliminated from the division race. In the Wild Card picture, they rank fourth, 2.0 games relative to the cut line — and per the same data, they have been eliminated from the Wild Card race as well. They have dropped their last two games heading into this homestand.

At 86-76 and out of both races, Arizona is not in a position where it can absorb a long-term rotation loss without consequence. A two-game losing streak heading into a home series against St. Louis is not a crisis, but it is not the momentum a team wants coming out of the break either. The Cardinals series offers a chance to arrest the skid with a rotation that, for this weekend at least, does not include Gallen.

What we don't know yet

The Diamondbacks have not announced what Gallen's injury is, how long he has been dealing with it, or when the second-opinion process is expected to conclude. The public comments from the club suggest it is in a waiting posture, not an announcing one — the evaluation will run its course before anything more definitive is said.

The Tyler Locklear recall, per azcentral's Nick Piecoro, adds a roster piece at first base, but the reporting does not connect that move directly to Gallen's situation. Roster construction in the second half involves a great many moving parts, and drawing a straight line between the two developments would be adding a fact the material does not supply. Under general roster mechanics, a player called up from Triple-A must be on the 40-man roster, and clubs managing multiple roster questions simultaneously often make moves that serve several purposes at once — but what specific purpose the Locklear recall serves beyond adding first-base depth has not been reported.

What the second opinions will find, when they will be complete, whether Gallen will require a procedure of any kind, and what his availability looks like for the remainder of the season — none of that has been reported. The evaluation is ongoing.

What to watch

The completion of Gallen's medical evaluation is the obvious thread to follow. When the Diamondbacks have something to announce, they will announce it; until then, the club's press availability will be the most reliable signal of where things stand. Any shift in the language — from "continuing to evaluate" toward something more definitive in either direction — would be meaningful.

On the field, the Cardinals series at Chase Field gives Arizona a chance to stop a two-game skid with a rotation that, for this weekend, does not include Gallen. How Kelly, Pfaadt, and Rodriguez perform in those three starts will matter both for the standings and for the broader question of what the back half of this rotation looks like if Gallen's situation extends.

The Locklear recall is worth tracking as well. First-base depth in the second half of a season has its own operational logic, and azcentral's Piecoro will likely have more detail on what that move means for the roster shape going forward.

For now, the Diamondbacks are home, the break is over, and the most important question in their organization does not have an answer yet.