Diamondbacks' starting pitching injuries are catching up to them

SAN DIEGO — Entering the 2024 season, the Diamondbacks appeared to have one of the better starting rotations in baseball, and a variety of worthy depth options waiting in the wings.

But, as the adage goes, you can never have too much pitching. And, two months into the year, the Diamondbacks seem to be running out.

With three-fifths of the starting rotation currently on the injured list in Zac Gallen, Merrill Kelly and Eduardo Rodriguez, the Diamondbacks’ starting corps currently consists of struggling left-hander Jordan Montgomery and a trio of youngsters in Brandon Pfaadt, Ryne Nelson and Slade Cecconi. Rookie left-hander Blake Walston had occupied the fifth spot, but he too hit the IL earlier this week. Newly recalled reliever Scott McGough will serve as an opener on Sunday in his place.

This is not the rotation that the Diamondbacks envisioned on Opening Day, and the on-field results have made that increasingly clear.

On Saturday night, Nelson needed 91 pitches to work 3 1/3 innings against the San Diego Padres at Petco Park. He allowed six runs (five earned) on six hits in a 13-1 blowout loss. It raised his season ERA to 5.96.

Nelson’s outing capped off a disastrous turn through the rotation, in which only one D-backs starter managed to complete five innings.

The latest turn through the Diamondbacks' starting rotation:

Walston: 4.1 IP, 2 ER
Montgomery: 2+ IP, 6 ER
Cecconi: 4.1 IP, 3 ER
Pfaadt: 5.1 IP, 5 ER
Nelson: 3.1 IP, 5 ER

As a unit, they combined for a 9.78 ERA and averaged under four innings per start.

— Jesse Friedman (@JesseNFriedman) June 9, 2024

“The past couple games have been a little bit of a grind,” Diamondbacks manager Torey Lovullo said. “We’ve been inspired by the understudies, and they’ve taken the baseball and they’ve done a really nice job. We are where we are because of that group. But I don’t want them to accept where they’re at. I want everybody to continue moving forward, getting better every single start, and not saying that ‘I’m comfortable.’ I want them to go out and prove it every single time.”

To be fair, few major-league teams are equipped to endure so many starting pitching injuries. Rodriguez has not thrown a pitch this year due to a shoulder injury. Kelly made only four starts before going down with a shoulder injury of his own. Gallen has missed two starts due to a hamstring injury.

Those absences, combined with Montgomery needing time to ramp up after signing late, have led to 28 games in which the Diamondbacks’ starter (or bulk reliever, when an opener is used) was one of the team’s depth options. That works out to 43 percent of the team’s games.

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To its credit, the Diamondbacks’ rotation seemed to be staying afloat until recently. As of May 26, it had an ERA of 4.25, which ranked 19th in baseball.

Since then, Diamondbacks starters have a 7.24 ERA and are averaging just under 4 2/3 innings per start. They have logged just one quality start in that span, that being Nelson’s previous outing against the San Francisco Giants. Their Diamondbacks’ team starting rotation ERA is now 4.76, which ranks 26th in baseball.

When asked if the Diamondbacks’ rotation injuries were bound to catch up with them eventually, Lovullo doubled down on his belief in his young pitchers, and their belief in themselves.

“Each person that’s sitting there getting an opportunity probably feels like they’re as good as anybody,” Lovullo said. “And I want them to think that. I’m very well aware of the names ‘Gallen,’ ‘Kelly’ and ‘Rodriguez.’ We know the quality of arm that we have every time they take the mound. But I want to coach up those guys and make sure that next-level guy needs to go out and do their job.”

So far, none of the Diamondbacks’ young starters have managed to separate themselves. Here is a look at their stats:

Pitcher	G	IP/G	ERA	WHIP
Ryne Nelson	11	4.7	5.96	1.69
Slade Cecconi	8	5.2	5.66	1.14
Tommy Henry	6	4.7	5.40	1.62
Blake Walston	3	4.2	2.84	1.42
Total	28	4.8	5.45	1.48

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That 5.45 combined ERA is subpar, but the most glaring stat here might be the unit’s 4.8 average innings per outing. That explains why the Diamondbacks bullpen has logged the seventh-most innings this season. Diamondbacks starters’ inability to pitch deep into games has been especially problematic during the team’s current run of 13 consecutive days without an off-day. The team has made a plethora of roster moves to make it work.

Of course, what makes this situation particularly tough for the Diamondbacks is the fact that the pitchers they are trying to replace have been exceptional in the past.

Here is a look at how Gallen, Kelly and Rodriguez performed in 2023:

Pitcher	IP/G*	ERA	WHIP
Zac Gallen	6.2	3.47	1.12
Merrill Kelly	5.9	3.29	1.19
Eduardo Rodriguez	5.9	3.30	1.15
Total	6.0	3.36	1.15

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Not only is their combined ERA about two full runs lower than the aforementioned group above, but this trio also averaged over a full inning more per outing. It is difficult to quantify the impact that can have on a team.

Of course, no team goes a full season without starters getting hurt. The Diamondbacks were going to need at least eight or nine starters to make it through the year no matter what. However, there is no question that they have been hurt by injuries more than most.

Unfortunately for them, it will be a while before their rotation is back at full strength. Gallen is eligible to be reinstated from the IL on June 15 and is seemingly on track to return before too long, but Lovullo pegged the All-Star break as a rough return estimate for both Kelly and Rodriguez. Montgomery is healthy, but has not pitched like his usual himself.

On the positive side, many National League teams have struggled this year, and the Diamondbacks’ 30-35 record still has them within two games of the playoff picture. There is more than enough time to turn things around.

For Lovullo, it begins with quality starting pitching.

“When the starting pitching is healthy and good,” Lovullo said, “we’re gonna put ourselves in a position to win baseball games. That’s where it starts and stops for me. It sets the tone for the day.

“But this happens in baseball. We lost a couple games in a row, and we can salvage the series [on Sunday]. And that’s what our expectation will be.”

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Top photo: Denis Poroy/USA TODAY Sports