Morejon was placed on the 10-day injured list with a left forearm strain Monday.
Morejon was removed in the first inning of Sunday's start against the Rangers due to his injury. The southpaw underwent an MRI, but the results of the test aren't yet known. The Padres plan to stay on turn in the rotation in the coming days, but Nabil Crismatt was recalled in a corresponding move and could fill in as a starter if needed.