Apostel has appeared in three games for Triple-A Round Rock since returning from a knee injury, going 3-for-12 with a solo home run, a double and a walk in those contests.
After debuting for Round Rock on April 5, Apostel was sidelined for two weeks before re-entering the lineup April 19. He's expected to play first base on a near-everyday basis for Round Rock now that he's healthy again.