D-backs' Young Starter Had Extreme Highs and Lows in 2025

Arizona's young righty had historically great and historically poor performances in 2025.

Sep 28, 2025; San Diego, California, USA; Arizona Diamondbacks starting pitcher Brandon Pfaadt (32) delivers during the first inning against the San Diego Padres at Petco Park. Mandatory Credit: Denis Poroy-Imagn Images | Denis Poroy-Imagn Images

The Arizona Diamondbacks' 2025 season was many things. One thing it was not was predictable.

A year that began with such high hopes collapsed into an 80-82 record, as the D-backs sat out of the playoff dance for the second straight season. Injuries, underperformance and generally unexpected turns appeared to cost Arizona at numerous points.

And perhaps no player had as extreme (in both directions) a season as young right-handed starter Brandon Pfaadt, who signed a five-year, $45 million extension ahead of 2025.

As Arizona Diamondbacks On SI continues to break down the individual seasons of every player that contributed to the 2025 D-backs roster, the below article will be updated with the proper links to every season review as they are published.

Related Content: Breaking Down Every Diamondbacks Player's 2025 Season

Arizona Diamondbacks 2025 Player Review: Brandon Pfaadt

Brandon Pfaadt 2025 and career stats | Alex D'Agostino.

Pfaadt's season began on a high note. The right-hander delivered Quality Starts in four of his first six outings, going 5-0 in five starts for the month of April. He ran into some trouble in May, but rebounded with a six-inning Quality Start and a win over the Los Angeles Dodgers.

And then, he took the mound on May 31 against the Washington Nationals. Pfaadt gave up six hits and hit two batters on the way to eight earned runs — all without recording an out. His 3.90 ERA leapt to 5.05. That led to a brutal stretch of starts in June, in which he posted a collective 6.26 figure.

But on July 9, in a critical road matchup with the San Diego Padres, Pfaadt tossed eight frames of two-run ball — his deepest start to that point. From there, it was a mixed bag, as he delivered some solid starts and some poor, until September 17.

On that day, facing the San Francisco Giants, Pfaadt threw nine shutout innings. He allowed only one hit while striking out seven in that game. It was the first time a D-backs pitcher had thrown nine innings since Zac Gallen did so two years prior in Chicago.

Unfortunately, a lack of offense did not award him a complete game shutout, and Arizona went on to ultimately lose that game. Few other occurrences could have so well encapsulated the D-backs' 2025 season.

But that was essentially Pfaadt's season — glimmers of pure excellence, but with a few too many explosive starts in between. With that said, he did post a 4.22 FIP and 4.01 expected FIP, which suggest he did pitch somewhat better than the ERA suggests.

Still, Pfaadt struggled with leaving pitches over the heart of the plate. Rarely did he issue a walk, but he also gave up 1.32 home runs per nine innings, as the long ball continued to plague the young righty.

Brandon Pfaadt: 2026 Outlook

Pfaadt is one of the X-factors on Arizona's pitching staff in the upcoming season. He's shown the ability to pitch at a very high level in the majors, and has eaten innings at a high clip, but he's struggled to maintain consistency in his young career.

If he's able to take the next step in that regard, he'll be one of the cornerstone arms in the D-backs' rotation. Limiting hard contact will be of major importance going into 2026.