After narrowly missing out on the postseason last year, the Arizona Diamondbacks embarked on an offseason that was both busy, but also extremely productive. Everyone knew entering the offseason how potent the offense could be, led by the likes of Ketel Marte, Corbin Carroll and Eugenio Suarez, along with how loaded their bullpen was on their best days, with Justin Martinez and A.J. Puk anchoring the backend. The area that carried some doubt however was the starting rotation, as beyond Zac Gallen the Diamondbacks rotation wasn’t anything special, whether that be because of younger arms with potential still finding their way in the big leagues like Brandon Pfaadt (4.71 ERA in 2024) or simply mediocre performing veterans like Merrill Kelly (4.03 ERA in 2024). As a result, their 2024 rotation sat 27nd in MLB in ERA (4.79), tied for 13th in FIP (4.01), 25th in WHIP (1.34) and 27th in BAA (.264). To combat this, they managed to pull off the one of the biggest deals of the offseason, after shocking the world and signing the most coveted arm on the open market in Corbin Burnes. Now suddenly with Burnes and Gallen leading the charge, arms like Kelly and Eduardo Rodriguez could revert to more middle of the rotation-type arms, while young starters like Pfaadt now had more protection around them to ease some of the pressure of being better than may’ve been capable of being off of them. Arizona suddenly looked, on paper, as though they had no apparent weaknesses. Fast-forward to the end of April though, and the D-backs have found themselves hovering around .500 at 14-13 entering gameplay on April 27. Not a bad place to be necessarily, but hovering around .500 isn’t what many had in mind for this team, especially entering the season in the top five of our Opening Day Power Rankings. A lot of this comes this comes down to their starting rotation, who in a lot of ways have improved from last year. However, similar to what a .500 winning percentage says, they’ve just been average and not nearly the top rotation we thought they could be this season. All statistics in this article were taken prior to games on April 28th. The Diamondbacks’ Rotation Has Simply Been Nothing Special Looking at the rotation from a broad point of view, the D-backs boast a middle-of-the-pack staff across the board. They sit tied for 23rd in ERA at 4.38 and 16th in FIP at 3.87. Things look a little better when it comes WHIP and BAA, but they still outside the top-10, as they’re 15th in WHIP at 1.26 and 18th in BAA at .238. Then from a strikeout and walk standpoint, it’s the same deal, but they’re at least able to crack the top-10. They sit 9th in K/9 at 9.00 and 10th in BB/9 at 3.09. This can change frequently though, as the club was sitting around 11th and 16th, respectively, prior to Sunday’s game. Looking at quality of contact now, their HR/9 rate sits 18th in the league at 1.14, as they’ve also surrendered the fourth-highest hard-hit rate at 33.4%. From an individual point of view it’s easy to see why this is the case, as apart from Pfaadt, it’s been a disappointing season for a majority of the staff. Burnes sits at a 4.05 ERA, 4.65 FIP, 1.35 WHIP and .240 BAA through his first five starts. He also holds his highest totals in BB/9 (4.05), HR/9 (1.35) and xERA (5.20) since becoming primarily a starter back in 2020. His co-anchor at the top of the D-backs rotation in Gallen has been even worse. Through six starts, the 29-year-old Opening Day starter has thrown to a very high 5.57 ERA, along with a 4.36 FIP, 1.39 WHIP and .236 BAA. He’s also walking the most batters he has in his career with a 4.18 BB/9 and his 1.39 HR/9 is the highest mark he’s held in the last four seasons. Then we move to the middle of the rotation, starting with Kelly. While a 1.10 WHIP and .197 BAA through six starts is nothing to be ashamed of by any means, he’s still just a mid-4.00 arm in both ERA and FIP this season (4.41 and 4.69, respectively), while striking out less than seven hitters per nine innings (6.89) for the first time in his MLB career. Rodriguez is the last disappointing looking arm. Like Kelly, his ERA also sits in the mid-4.00s (4.40) and in his case, he doesn’t have the same respectable WHIP and BAA as a redeeming quality, with a 1.29 WHIP and .259 BAA. If it weren’t for Pfaadt and his 2.78 ERA and 1.12 WHIP performance doing some serious heavy lifting for this group through his opening six starts, who knows where this staff would be. The D-backs Staff Still Has the Makings to be a Strength As lackluster as the rotation may look now in Arizona, it’s important to remember that the MLB season is a marathon, not a sprint. Despite a poor start to the year, there’s plenty of silver linings to fall back on here with this group. Burnes and Gallen are simply too good of pitchers to throw the way they’ve been throwing in March/April for the entirety of the season. Burnes threw to sub-3.00 ERAs and sub-1.10 WHIPs in four of his previous five seasons entering 2025, while Gallen threw to a sub-4.00 ERA and sub-3.50 WHIP in each of his last three seasons from 2022 to 2024. Kelly’s ERA is tainted by a 3.0 inning start where he surrendered nine earned runs against the Yankees on April 3. Apart from that, he’s managed to go at least 5.1 innings in his five other starts surrendering no more than two earned runs and four hits in each. Rodriguez is the cream of the crop of the starting staff when it comes to inducing strikeouts, with 10.67 K/9, on pace to be his highest career mark. A 2.75 FIP and 2.85 xERA shows he’s also been getting relatively unlucky this season. And at the end of the day, Pfaadt is looking every bit worthy of that five-year extension he inked at the very start of the season. The tools are in place for this staff to be better and make this team the National League powerhouse many thought they could be at the start of the season. It’s now a matter of when this rotation will play up to their potential and be that strength, because a prolonged stretch of this kind of play could see them fall further out of contention, especially given the way their NL West rivals in the Dodgers, Giants and Padres have each come out flying to start the season.