Yacabonis will start Thursday's game against the Angels, Nathan Ruiz of The Baltimore Sun reports.
Tom Eshelman was previously announced as the starter, but Yacabonis will instead take the mound. Yacabonis worked as an opener earlier this season, but the Orioles haven't indicated whether that's the case this time around. The 27-year-old may not be fully stretched out as a starter, but he did deliver 61 pitches in an appearance July 13.