What D-backs' Big Series Win vs Rockies Told Us — And What It Didn't

An impressive series win in some ways, and a discouraging one in others.

May 15, 2026; Denver, Colorado, USA; Arizona Diamondbacks starting pitcher Merrill Kelly (29) delivers a pitch in the ninth inning against the Colorado Rockies at Coors Field. Mandatory Credit: Ron Chenoy-Imagn Images | Ron Chenoy-Imagn Images

The Arizona Diamondbacks earned a somewhat stressful, but still decisive series win over the Colorado Rockies in Coors Field, taking two of three games.

Though it was not the prettiest series for the Diamondbacks, it was a series win they badly needed. Sweeping is hard to do in baseball, against any opponent.

Here's what the series win in Denver told us about the D-backs, and two questions that have arisen as a result:

What Diamondbacks' series loss to Rockies told us

1: Merrill Kelly isn't finished, yet

May 3, 2026; Chicago, Illinois, USA; Arizona Diamondbacks pitcher Merrill Kelly (29) pitches against the Chicago Cubs during the first inning at Wrigley Field. Mandatory Credit: Patrick Gorski-Imagn Images | Patrick Gorski-Imagn Images

Veteran right-hander Merrill Kelly came in to this series at a turning point in 2026. After a brutal start to his season, Kelly found some success against the New York Mets one start prior, but needed to show that he was capable of moving forward with consistent success.

All he did to quiet those questions was throw his first career complete game at age 37, earning a game one win with nine efficient innings and one earned run allowed.

Kelly's location, as well as his trademark changeup were much sharper, and while he did benefit from some good defense, the fact is the right-hander was able to live in the zone and pitch to contact again without being banged around. He landed 73 of his 100 pitches for strikes, and kept his fastball velocity in the 93 MPH region even in his final inning.

There was some hard contact, but that type of outing (after a previously excellent outing) is not insignificant to Kelly's hunt for a rhythm on the mound.

2: The offense is in there, somewhere

May 11, 2026; Arlington, Texas, USA; Arizona Diamondbacks right fielder Corbin Carroll (7) slides into second base with a double against the Texas Rangers during the first inning at Globe Life Field. Mandatory Credit: Raymond Carlin III-Imagn Images | Raymond Carlin III-Imagn Images

Arizona's poor offense has been one of the biggest concerns of late. In fact, the pitching staff has been nowhere near the most egregious contributor to recent losses.

The Diamondbacks' offense does have talent, and they did put forward two sturdy showings at the plate — sandwiched around a brutal game two performance.

Arizona scored nine runs in game one, then plated eight in game three to win both of those games. Corbin Carroll roared to life with a two-homer game in game three, and Gabriel Moreno had an outstanding 5-for-9 series.

Even the struggling Ketel Marte had a two-hit game. Ildemaro Vargas went 4-for-4 in the opener, and Lourdes Gurriel Jr. hit his first homer of the year in a 5-for-12 series.

The offense is in there, somewhere; it's just not consistent, nor has it been particularly clutch.

Questions remaining after Diamondbacks' series win over Rockies

1: Which version of the offense is the real one?

May 13, 2026; Arlington, Texas, USA; Arizona Diamondbacks second baseman Ketel Marte (4) slides into third base during the third inning against the Texas Rangers at Globe Life Field. Mandatory Credit: Jerome Miron-Imagn Images | Jerome Miron-Imagn Images

As above mentioned, the Diamondbacks rapped out plenty of base knocks and had two excellent games at the plate — in a very offense-heavy ballpark, against a lower-quadrant pitching staff. That is encouraging, yes.

But game two was simply such a discouraging look that it's hard to expect the results from game one and three to be the norm moving forward. In game two, the Diamondbacks stranded an unbelievable 10 baserunners, and only managed to record one RBI base hit. They went 2-for-11 with runners in scoring position.

Which version of Arizona's offense is the real one moving forward will be critical. There's hope that the stars are finding their swings again, but that is quite tentative, for now.

2: What is Brandon Pfaadt's role moving forward?

May 12, 2026; Arlington, Texas, USA; Arizona Diamondbacks pitcher Brandon Pfaadt (32) comes on during the sixth inning against the Texas Rangers at Globe Life Field. Mandatory Credit: Andrew Dieb-Imagn Images | Andrew Dieb-Imagn Images

Brandon Pfaadt has not been dealt an easy hand this season, to say the least. But the unfortunate reality of this game is there's simply not much room for a player incapable of giving his team some amount of production.

Pfaadt struggled as a starting pitcher this season. He's had some solid outings since being shifted to a relief role, but his game three performance against the Rockies was a discouraging step back.

The righty allowed two base hits, a walk and a hit-by-pitch in the eighth inning of what was an 8-2 lead. He was only able to get one out, and was eventually charged with four earned runs after two inherited runners scored off Taylor Clarke.

Pfaadt's ERA on the season is 6.34. While there is undeniably talent there, it's a difficult look for a long reliever to only manage one out in what was, at one point, a blowout of a lead. If not for Clarke and Paul Sewald's bounce-back save, things might have turned disastrous.

The benefit to putting Pfaadt in the bullpen was to, hopefully, get his best stuff right away, and avoid the late-inning blowups. But if the blowups can happen at any time, in a game the Diamondbacks need to hold a lead, there may be a tough decision Arizona has to make with regard to the right-hander.