The Arizona Diamondbacks’ identity has been rooted deeply in unpredictability for some time now. The 2026 season has not been much of a deviation from those tendencies.

The Diamondbacks are 11-8, fresh off three straight series wins over the Mets, Phillies and Orioles. They have not lost a series since their three-game sweep in Los Angeles to open the season — which means they are 11-5 in their 16 games not against an infallible Dodgers club.

It’s starting to feel like cautious optimism in the valley, and for good reason. But how much can this Diamondbacks club really be trusted?

Let’s break it down:

2026 Diamondbacks Confidence Meter

Starting Rotation

Confidence level: 6/10

The Diamondbacks’ starting rotation has been quite sturdy to this point in the season. Righty Ryne Nelson is rounding back into his elite form after some early hiccups, Eduardo Rodriguez looks much-improved, Zac Gallen’s ERA is below 4.00 after four starts and Michael Soroka has had a historic early stint with Arizona.

It still feels a little early to expect much out of this group, however. Gallen’s underlying metrics (including a 6.25 expected ERA) do suggest his results may not be sustainable. He’s striking out fewer batters than ever and giving up an average batted ball velocity of 93.1 MPH; that is a bottom-10% number.

Soroka, though holding a 2.87 ERA with 23 strikeouts in his first three D-backs outings, is still a wild card — both in terms of health and results. His expected ERA is 5.28, though his FIP is 2.78. Rodriguez’s turnaround looks legitimate in a number of ways, but it will be hard to shake the 5.00-plus ERA track record from skeptics.

This group did, however, just get its most consistent arm back. Merrill Kelly, despite not having his best stuff or command, pitched 5.1 innings of two-run baseball in his 2026 debut Tuesday. Even if it’s not his best year, the D-backs almost always know what they’re getting out of Kelly every fifth day.

Cautious optimism is a good way of describing this area of the Diamondbacks. There is hope that some of these results will be sustainable, and that the return of Corbin Burnes mid-season might bring an even bigger boost. Arizona might not end the year with the best rotation in baseball, but Diamondbacks fans can feel confident it won’t be the worst.

Offense

Confidence level: 8/10

The Diamondbacks’ offense is producing runs at the right times, in the right ways — and they’re not performing anywhere close to their ceiling.

In fact, Arizona ranks in the bottom-10 of MLB in OPS (.687), home runs (15) and on-base percentage (.291). And yet, they rank 10th in the majors in RBI (81) and have the sixth-highest team slugging percentage (.396). They’ve been scoring runs without being overly reliant on homers, which is more of an argument in favor of sustainable future production.

Now, it’s fair to wonder if regression is coming for some contributing hitters, such as Ildemaro Vargas (1.068 OPS), Jose Fernandez (.306 batting average) and Adrian Del Castillo (.923 OPS).

That is a factor that could become a negative trend. Until, of course, one realizes that Ketel Marte and Geraldo Perdomo — two of Arizona’s top hitting stars — have struggled immensely to begin the year. Those early-season woes haven’t seemed to hit Corbin Carroll, who’s hitting .311/.394/.607 with 11 extra-base hits.

It’s also worth noting that Arizona’s lineup is riddled with injuries; they’re missing Pavin Smith, Gabriel Moreno, Jordan Lawlar and Lourdes Gurriel Jr.

So no, some early poor numbers and a chance at regression is not enough to shake the confidence in a group that has been among MLB’s best for three seasons. At full strength, this could be a much more dangerous unit.

Bullpen

Confidence level: 5.5/10

The Diamondbacks’ bullpen is a coin flip. That’s essentially what it feels like the baseball gods do every time an Arizona reliever enters the game. And yet, despite the track record of abysmal, heartbreaking late-game meltdowns, the Diamondbacks have been quietly shutting down their opponents in the later innings at a much higher rate this season.

Arizona’s bullpen ERA is 4.81 — 22nd in baseball. Take away the five earned runs by catcher James McCann in the ninth inning of a blowout loss, and that ERA becomes 4.21, which would rank 17th. Remove the six earned runs allowed by DFA’d righty Joe Ross in his meltdown inning against the Tigers, and it’s 3.43, which would rank 10th.

On the other hand, the Diamondbacks have blown six leads this year, and watched a 7-1 score over the Orioles collapse into a 9-7 loss in two innings. The meltdowns have happened, and that outcome always appears to be a serious possibility in a close situation.

But some of the D-backs’ arms are excelling. Ryan Thompson has not allowed an earned run. Juan Morillo is throwing more strikes and has a 3.00 ERA. Taylor Clarke hasn’t given up a run since his four-run blowup at Dodger Stadium, and Paul Sewald leads the National League with a 6-for-6 conversion rate in ninth-inning saves.

There is a long, long way to go before this group becomes truly trusted, but there is much more reason to trust so far in 2026 than in prior seasons, with both Justin Martinez and A.J. Puk expected to return at some point this year.

Defense

Confidence level: 8.5/10

In this area, the Diamondbacks appear to be heading back in a positive direction. Reinforcing their previously-great defense was a high priority coming into the 2026 season, and that department certainly looks much sharper already.

Arizona holds the eighth-most Fielding Run Value (+8) in the majors, and the 10th-most Outs Above Average (+2).

The D-backs have a platinum glover at third base in Nolan Arenado. Alek Thomas is playing excellent defense again with +5 Defensive Runs Saved already — leading the majors in center. Jorge Barrosa has been sharp in the outfield, and the Fernandez-Vargas platoon at first base looks sharp and athletic. Even Ketel Marte is playing better second base than ever before, with +5 FRV and +2 DRS so far.

The main concern defensively is Geraldo Perdomo. Perdomo’s defense at shortstop has been somewhat lacking. He’s posted a -1 FRV, -1 OAA and -2 DRS at the ultra-premium shortstop position. Perdomo will be the biggest x-factor in the continued success of this infield.