Zac Gallen's Start vs Giants Tells a Lot About What He Can Still Do

The Diamondbacks need to see more of this from their former ace.

May 12, 2026; Arlington, Texas, USA; Arizona Diamondbacks pitcher Zac Gallen (23) heads to the dugout after striking out three during the first inning against the Texas Rangers at Globe Life Field. Mandatory Credit: Andrew Dieb-Imagn Images | Andrew Dieb-Imagn Images

It wasn't an elite start, nor did he look exceptionally sharp. But Zac Gallen did exactly what the Arizona Diamondbacks needed on Monday night against the San Francisco Giants.

Gallen is coming off one of the more brutal starts of his season, in which he gave up seven runs to the Texas Rangers in 4.2 innings. Three of those runs were changed to unearned several days following that game.

But on Monday night, Gallen was faced with a bottom-feeding Giants offense, and was spotted a 4-0 lead as a result of Nolan Arenado's grand slam before ever taking the mound in the first inning.

And while Gallen certainly did not pitch like the ace he once was, he did exactly what the Diamondbacks needed — provide length, and keep the game under control.

And that's all Arizona really needs out of their veteran right-hander, at this stage of the season. With plenty of recent success from all four of Arizona's other starting pitchers, all Gallen needs to do is provide solid, if not flashy starts for a newly-surging offense.

Diamondbacks' Zac Gallen delivers solid start against Giants

May 7, 2026; Phoenix, Arizona, USA; Arizona Diamondbacks pitcher Zac Gallen (23) throws against the Pittsburgh Pirates in the first inning at Chase Field. Mandatory Credit: Rick Scuteri-Imagn Images | Rick Scuteri-Imagn Images

Gallen got through six innings on Monday, and allowed two earned runs on four hits and a walk. He picked up eight whiffs, and landed 16 pitches for called strikes. It was his first official quality start since his second outing of the year on April 1. Gallen lowered his ERA to 4.78 in the process.

It was a solid start, by all means. His damage came in the form of a first-inning solo homer off the bat of Willy Adames, and a sacrifice fly that rewarded a leadoff double in the third, which made it a 5-2 game for Arizona at the time.

He also gave up six balls hit 100 MPH or harder. Only three went in the air, with one being Adames' homer.

Is that truly Gallen's best possible outcome at this stage of his career? Not likely. There's still the off chance of a legitimately dominant outing. But Gallen has no longer looked like the arm capable of blanking an opponent over seven innings, or punching out more batters than he completes innings nearly every start. And that's okay. That's not what the Diamondbacks need out of him.

What they do need is an arm who can walk out there every fifth day and avoid a blowout — an arm that can provide enough innings to secure a large lead, or at the very least prevent an emptying of the bullpen in a loss.

For a pitcher as talented as Gallen is, that may feel like a reduction. But Arizona has been seeing such high levels of success out of their rotation — Eduardo Rodriguez, Merrill Kelly, Ryne Nelson and Michael Soroka — in recent games.

All they really needed was for Gallen to carry his end of the bargain. Monday's start showed Gallen is more than still capable of doing that.