This Concerning D-backs Trend is Becoming Impossible to Ignore

The Arizona Diamondbacks have a serious pitching problem, but it's not the same one the D-backs faced in the 2025 season.

In 2025, the D-backs starting rotation — despite some admittedly poor run-prevention results — managed to provide one thing above all else: length. Arizona ranked second in the majors in innings per start at 5.5 last season, behind only the Philadelphia Phillies.

But that trend has begun to waver in recent days in 2026, and it's beginning to carry a ripple effect. Coming into Thursday's game against the Milwaukee Brewers, D-backs starters were providing an average of 5.0 innings per start — just below the 5.1 league average marker.

That average went down on Thursday, after Michael Soroka completed just three frames in his start. No D-backs starter has completed the sixth inning in a game since Soroka did so on April 17 against the Blue Jays, and the rotation holds an abysmal 10.69 ERA through its last nine starts.

These are not facts that are conducive to winning, particularly with a lower-end bullpen, as well.

Diamondbacks' lack of rotation length is a problem

Apr 28, 2026; Milwaukee, Wisconsin, USA; Arizona Diamondbacks pitcher Merrill Kelly (29) delivers a pitch against the Milwaukee Brewers in the first inning at American Family Field. Mandatory Credit: Michael McLoone-Imagn Images | Michael McLoone-Imagn Images

The Diamondbacks have gotten success from some of their starters, and some of their relievers, as well. But the fewer innings a starter can cover, the more innings are bequeathed to a leaky relief corps, and even the more successful bullpen arms can begin to tire, break down physically or underperform.

As a result of the lack of length, the D-backs' bullpen has had to adapt in its taxed state, with mixed results.

"We believe in our starting pitchers, but we know that they set the tone," manager Torey Lovullo told D-backs.TV's Todd Walsh following Arizona's most recent blowout loss to the Milwaukee Brewers.

"We've got to get better starting pitching, that's what it comes down to. We've been flooding our bullpen and asking a lot of them. It's worked out, we won a game here, but that's not our end zone, that's not our goal."

Why D-backs starters aren't going deep in games

Apr 1, 2026; Phoenix, Arizona, USA; Arizona Diamondbacks pitcher Zac Gallen in the first inning against the Detroit Tigers at Chase Field. Mandatory Credit: Mark J. Rebilas-Imagn Images | Mark J. Rebilas-Imagn Images

The lack of starter length can be attributed to a variety of factors, but a lack of strike-throwing is the primary culprit. Eduardo Rodriguez walked four batters on Wednesday, and was lifted after 4.2 innings on 87 pitches as the fifth inning began to unwind on him.

Merrill Kelly, who has his own concerning command issue during his first three starts, needed 104 pitches to get through five innings Tuesday, thanks to an astounding five bases on balls.

In total, Arizona's starting pitchers landed just 157 of their 270 total pitches for strikes in their last three-game series in Milwaukee — a mere 58% strike percentage.

Zac Gallen, meanwhile, was pitching efficiently through three innings in his most recent start, but was forced to leave ahead of the fourth after he was hit by a comebacker.

The Diamondbacks have, to a certain degree, been getting somewhat unlucky at times. But there is a distinct lack of efficiency present, and it stems from their ability to live in the zone. That will need to change to avoid a further devolution of both rotation and bullpen numbers — which are already less than favorable.

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