The Arizona Diamondbacks did not have an entirely unsuccessful 2026 season, finishing 10 games over .500 at 86-76.
They did, however, fall short of their ultimate goal - making the postseason for the first time since their miracle run to the World Series in the 2023 season.
Arizona received contributions up and down the order, and even from some surprising areas of the roster - both on the pitching side and the position-player side.
But there were a handful of players who fell a bit short of expectations this past season, even if they managed to be productive overall.
All of these players are - for now - under contract in 2027. The Diamondbacks need bounce-back years from each of them. Here they are:
Sep 23, 2026; Denver, Colorado, USA; Arizona Diamondbacks starting pitcher Merrill Kelly (29) delivers a pitch in the first inning against the Colorado Rockies at Coors Field. Mandatory Credit: Ron Chenoy-Imagn Images | IMAGN IMAGES via Reuters Connect
Merrill Kelly had some positive moments in 2026 , but did not perform up to his usual, reliable standard.
Kelly, who is known for being consistent, was anything but. He pitched to a 4.94 ERA over 29 starts - by far the worst such figure in his eight-year major league career.
He began the year in the IL due to intercostal nerve irritation in his back, which forced him off the role of Opening Day starter. He never quite seemed to find his rhythm after that, as his command and stuff appeared to fail him at inopportune moments.
His best month was July, in which he produced a 1.95 ERA over five starts. But that quickly vanished with rough numbers in both August and September. Kelly is under contract in 2027 with an option for 2028. An offseason reset could be helpful, though at 37 years old, it could simply be natural decline.
Sep 27, 2026; San Diego, California, USA; Arizona Diamondbacks second baseman Ketel Marte (4) reacts after lining out during the third inning against the San Diego Padres at Petco Park. Mandatory Credit: Denis Poroy-Imagn Images | IMAGN IMAGES via Reuters Connect
Ketel Marte did not have an abysmal season at the plate and he played very strong defense at second base. But it was nothing close to the output he's provided in recent seasons.
Marte hit .249/.316/.432, good for a .748 OPS and 22 home runs in 2026. Those numbers were, mostly, the worst he's posted since a major down season in 2022. His superstar factor was held in check, outside of some dramatic walk-off moments.
There was, of course, the drama surrounding his unexcused absence; the Diamondbacks are going to have to approach him differently in 2027 . But on the field, his production simply was not what Arizona is used to seeing.
Sep 27, 2026; San Diego, California, USA; Arizona Diamondbacks shortstop Geraldo Perdomo (2) looks into the stands after hitting a fly ball during the sixth inning against the San Diego Padres at Petco Park. Mandatory Credit: Denis Poroy-Imagn Images | IMAGN IMAGES via Reuters Connect
Geraldo Perdomo did not have an overall poor season in 2026. In fact, he was worth 5.0 FanGraphs WAR, playing excellent shortstop defense.
But after a fourth-place MVP finish in 2025 , alongside 20 homers and 100 RBI, his slash took a dive in 2026. He hit .262/.370/.377 with just nine homers and 59 RBI.
But where the Diamondbacks truly need improvement is in his situational hitting. Perdomo hit .331 with runners in scoring position in 2025 and is a career .271 in that situation. He has been one of Arizona's best situational hitters, even when his overall numbers have been poor.
But in 2026, that dropped all the way to .186. He was simply not a threat with RISP, and that was the major concern with the Diamondbacks' disappointing offense all year. Hopefully for Arizona, he can get back closer to his previous season - or at least his career average.
This article was originally published on www.si.com/mlb/diamondbacks/onsi as 3 Players the Diamondbacks Desperately Need More Out of In 2027 .
