These 2 Expensive Mistakes Are Crushing Diamondbacks' Playoff Hopes

Zac Gallen's rough 2026

Arizona signed Gallen to a one-year deal worth the equivalent of his declined Qualifying Offer. Part of that $22.025 million salary is deferred, so he's only costing a little over $16 million this season. But to be blunt, Gallen hasn't been worth that.

Gallen has posted -0.6 aWAR (the average of Baseball Reference and FanGraphs WAR) this season. The 6.10 ERA — which is the worst qualified figure by a starter in baseball — speaks for itself. He's on his way to a second-straight season of career-worst numbers, provided an unexpected turnaround does not occur.

His expected ERA (5.69) and FIP (4.97) suggest he's not getting unlucky, as does his 1.47 home runs per nine innings. His career-low 14.3% strikeout rate and 19.7% whiff rate beat the drum a little harder, while his four-seam fastball has become a completely ineffective pitch.

Gallen is 3-6 this season, and Arizona is 3-4 during games where he recorded a no-decision. Pitcher wins are hardly the stat they once were, and there is some dishonesty in pitcher losses, but the objective fact is Arizona has lost 10 of the 16 games in which Gallen has taken the mound.

He's given up four or more runs in nine of those 16 starts, with only three official Quality Starts in the process. He has not completed the seventh inning once this season, and he's the only D-backs starter not to do so. His last outing saw him give up a career-high nine runs in four innings in a blowout loss to the Twins.

Merrill Kelly doesn't look like himself

Kelly, meanwhile, signed a more lucrative deal. He rejoined the Diamondbacks on a two-year contract worth $40 million, with a vesting option for 2028.

The 37-year-old right-hander had been traded away at the 2025 deadline to the Rangers, but returned to his hometown club in hopes of finishing his career as a Diamondback. Despite being initially tabbed the D-backs' opening day starter, Kelly's 2026 season began on an inauspicious note.

Kelly went down on the IL with intercostal nerve irritation in his back, which sidelined him until April 14. He's been inconsistently volatile since then, which is a direct 180 from his "mainstay" calling-card. He holds a 5.81 ERA, a 7.44 expected ERA and a 5.98 FIP this year. Those are all career-worsts.

Perhaps a longer runway from the IL might have helped soften the three-straight blowups from April 21-May 3, but it's no longer a small sample size that's inflating his numbers. He's been hit very hard, and has given up six-plus runs in two of his last three starts.

He's striking out a career-worst 13.8% of batters, and simply doesn't seem to have the sharpness in his location that allowed him to pitch to contact around the edges of the zone the way he used to. That has all added up to an average WAR total of -0.45 and an ERA+ of 73 — 27% below average.

Is there hope for Gallen and Kelly?

Gallen's decline has been evident for some time — arguably, the middle portion of 2024. He had a career-worst season in 2025 and did not garner enough free agent interest to earn a lucrative long-term deal.

His issues have been broken down many times on this website; there does not appear to be a tweak or adjustment that could turn him back into an ace, or even an above-average starter, though one simply cannot predict what will happen next. He did pitch six innings of three-run baseball his last time out, after all.

Kelly is a different story. He's never quite looked this rough before, and the decline has hit quite suddenly. It's possible he's still dealing with a physical ailment that's hindering his command, but he's also 37, and regression can strike in an instant for pitchers of such veteran status.

Kelly feels like a safer bet to find some level of consistency, even if it's closer to average than elite. He also pitched his first-ever complete game in Coors Field on May 15, so there may still be something left in the tank. The concern is more-so that his less-sharp outings have been disastrous, rather than simply below-average, which has not been a regular occurrence in his career.

This is not to take anything away from either of these players' D-backs careers. They have contributed to some of the best moments in this team's recent history, and their overall body of work in an Arizona uniform is positive. That should be remembered despite their results.

The loss of both Soroka and Ryne Nelson to the injured list nearly guarantee both of these arms are safe, for now. Jose Cabrera's MLB debut provided some confidence, as well. However, tough conversations may have to happen sooner than later. Unfortunately, there are not many truly realistic rotational options left that could afford parting with both.

Corbin Burnes won't be back by the All-Star Break after all. Brandon Pfaadt — who has not been good this season, either — is still working on getting stretched back out to full starting length in Reno. The minor league replacement players are either still raw, injured or struggling.

But once playoff crunch time does arrive, the Diamondbacks may be looking back at quite a heavy handful of games that were lost by way of poor outings by their previously-elite veteran arms. Those games could be the difference between a playoff berth or another disappointing season.