Mitch Bratt’s early exit Sunday against the Cincinnati Reds provided a fitting image for the problems currently surrounding the Arizona Diamondbacks’ starting rotation.

The rookie left-hander lasted only three ineffective innings, in which he allowed three runs on three hits with three strikeouts and three walks. He added another concern to a pitching staff already dealing with significant uncertainty.

Earlier Sunday, Arizona learned that Michael Soroka would return to the Injured List because of right arm inflammation.

Soroka’s setback is only the latest in a long series of blows to the rotation, and it leaves the Diamondbacks with serious questions as September approaches.

Without Soroka, Arizona’s current rotation projects to include Eduardo Rodríguez, Brandon Pfaadt, Merrill Kelly, Bratt and either Kohl Drake or Jose Cabrera, barring an unexpected addition.

Rodríguez owns a 2.61 ERA in 155 innings, while Pfaadt has a 3.39 ERA in 98.1 innings. Kelly sits at 5.35 in 134.2 innings, Bratt at 4.54 in 39.2 innings, Drake at 5.40 in 16.2 innings and Cabrera at 5.60 in 17.2 innings.

The rotation has improved considerably overall this season, but much of that success has come from Rodriguez’s career year and Pfaadt’s 1.80 ERA in 55 innings over nine starts since returning from the minor leagues.

Kelly has struggled throughout the season, while the rookie starters have encountered predictable difficulties.

Soroka’s 3.40 ERA in 95 innings had provided an important boost, but recurring injury problems continue reducing his value.

Arizona also has very little remaining depth.

Drake and Cabrera are both in the minor leagues and neither has pitched particularly well recently. Bratt’s performance Sunday has been closer to his normal level than his seven-inning shutout against the San Diego Padres on August 5.

Zack Littell was signed to provide long relief and potential rotation depth, but he posted a 7.50 ERA and 2.08 WHIP in 12 innings across three appearances before being designated for assignment Sunday.

He could remain in the organization, but he is hardly an obvious answer.

Corbin Burnes, Zac Gallen and Ryne Nelson are progressing toward returns.

However, after lengthy absences, expecting any of them to immediately provide long and fully effective starts in 2026 would be unrealistic.

Pitchers returning from significant injuries often require time to regain command, movement and velocity.

Even if Burnes pitches in September, the former Cy Young winner may not immediately resemble his best version and will likely be limited well below six innings.

Nelson could return in a bullpen role after a non-Tommy John elbow injury. He already carried a 4.97 ERA in 83.1 innings before going down.

Gallen has struggled since 2024, and his 6.34 ERA in 98 innings while healthy was the worst in MLB before his injury.

Arizona still has time for their young arms to improve, for struggling veterans to rebound and for the rotation to stabilize enough to support an October run.

None of it is guaranteed.

If the Diamondbacks are going to reach the postseason, their starting pitching will need to become considerably more reliable.