Delgado appeared in one game with Double-A Mobile during a brief rehab assignment and fanned two in a scoreless inning. He also threw one inning for the team's entry in the Rookie-level Arizona League.
In 41 appearances in relief for the D-backs this year, Delgado is 4-3 with a 2.79 ERA, and he had a 0.66 ERA in his 12 outings prior to the injury.
Romak was informed of the demotion following Sunday afternoon's 2-1 loss to the Braves in Atlanta. He started one game and appeared in five others, going 3-for-10 with a double.
Steve Gilbert is a reporter for MLB.