Ullola will serve as the opening pitcher during Friday's game against the Rays, Matt Kawahara of the Houston Chronicle reports.
Ullola has allowed three earned runs in seven frames in the big leagues, and he's now been granted the opportunity to make his first career MLB start. The 24-year-old righty spent most of his minor-league career as a starter but transitioned to relief this season and hasn't worked more than two innings in an appearance since mid-May, so his outing Friday will likely be a brief one.