Biggest Unresolved Concern for the Diamondbacks Before Opening Day

The Arizona Diamondbacks are slowly beginning to round into shape, with opening day less than a full week in the distance.

And yet, Arizona's biggest concern of the offseason feels hardly any closer to a resolution. Of course, that would be the bullpen, whose relievers struggled to a fourth-worst 4.82 ERA in the 2025 season.

Much of that can be attributed to injuries. But two of the most impactful injuries — to leverage arms Justin Martinez and A.J. Puk — will continue to linger well into the 2026 season.

The Diamondbacks have, by way of technicality, added to their relief corps this offseason. But they hardly did so to an extent that would inspire confidence in the bullpen's performance in the upcoming season.

Arizona Diamondbacks' Bullpen Still a Concern

Arizona Diamondbacks pitcher Kevin Ginkel throws to the Los Angeles Dodgers in the ninth inning at Chase Field in Phoenix, on May 8, 2025. | Rob Schumacher/The Republic / USA TODAY NETWORK via Imagn Images

So far in spring training, the Diamondbacks have the third-worst ERA in baseball — a 6.71 figure that's only an improvement over the Seattle Mariners and lowly Colorado Rockies.

Spring training results do not ultimately matter, and are hardly an indication of future success. But it is worth noting that two of the D-backs' expected top back-end arms have had abysmal outcomes in the Cactus League.

Righty Ryan Thompson, whose sinker has averaged under 90 MPH in velocity, currently holds a 6.14 ERA. That is a concern despite the low-stakes environment, as Thompson has never posted a spring ERA of over 3.00, and averages a 1.89 for his eight Cactus League seasons.

Right-hander Kevin Ginkel is, perhaps, even more of a concern. His fastball has struggled to even reach 95 MPH, and his results have been brutal. A 11.81 with 14 hits surrendered in seven games has significantly hurt his chances of being Arizona's closer in 2026.

Left-hander Brandyn Garcia has a 13.50 ERA. He has walked six batters and hit two over his last three games; he's only thrown 34 of 77 pitches for strikes in those outings, as well.

And beyond those arms, there is still a somewhat small pool depth — at least, at the major league level.

Diamondbacks' Bullpen Additions

Arizona Diamondbacks pitcher paul sewald — Arizona Diamondbacks pitcher Paul Sewald during spring training workouts at Salt River Fields on Feb. 16, 2026, in Scottsdale. | Rob Schumacher/The Republic / USA TODAY NETWORK via Imagn Images

Arizona brought in two of their former arms this offseason: right-hander Taylor Clarke and former World Series closer Paul Sewald. Clarke is coming off a career year, while Sewald is multiple seasons removed from being a lockdown closer option.

Clarke has been exceptional in spring training, posting a 1.17 ERA and 0.78 WHIP in 7.2 Cactus League innings, but he also has a career ERA of 4.73, and has only posted results below a 4.00 in one season — his most recent.

Even with a newly-upgraded changeup, Clarke is not exactly a ninth-inning arm.

Sewald, of course, appears to be on a collision course with the closer's role once again. Though not named Arizona's closer, Torey Lovullo has implied it. Sewald's velocity is back up in the 91-93 MPH range after sinking down around 90 MPH in 2025, which is encouraging, but not a guarantee of save-situation success.

And then there's righty Kade Strowd. The D-backs invested a legitimate asset in the right-hander by sending Blaze Alexander to Baltimore in order to acquire him. Strowd has struggled immensely, with a 10.57 ERA in eight games.

On the more positive end, right-hander Jonathan Loáisiga (the former Yankee) is an arm to keep an eye on for late-inning opportunities. His fastball reached 99.6 MPH in Thursday's game against the White Sox.

Loáisiga has allowed three runs in seven games this spring. Perhaps more importantly, he's struck out seven against only two walks. If Loáisiga, who is on a minor league deal currently, can simply remain healthy, he will automatically be one of the D-backs' best back-end options in terms of stuff and strike-throwing ability.

Diamondbacks' Currently-Rostered Sleepers

Arizona Diamondbacks right-hander Andrew Hoffmann (56) pitches against the Seattle Mariners at Salt River Fields on March 9, 2026. | Joe Rondone/The Republic / USA TODAY NETWORK via Imagn Images

While the depth is thin, Arizona does have some young hurlers who could be in line for a step forward.

Righty Andrew Hoffmann — who came over at the 2025 Deadline — has a 2.57 ERA with 10 strikeouts in seven innings this spring. He appears poised to make the major league roster after a difficult end to 2025 in a small sample size.

Left-hander Philip Abner may, if Garcia's issues persist, end up being the D-backs' lone southpaw. Abner jumped three levels in 2025, going all the way from High-A to the majors. He allowed two runs in five MLB appearances, and has 11 strikeouts in 8.2 Cactus League innings.