The Astros recalled Ullola from Triple-A Sugar Land on Sunday, Chandler Rome of The Athletic reports.
The 24-year-old right-hander has yet to make his big-league debut, but he'll provide the Astros with a fresh bullpen arm ahead of Sunday's series finale in Detroit. Since signing with the Astros out of the Dominican Republic in 2021, Ullola has largely served as a starter during his time on the minors, but he was moved to the bullpen at Sugar Land in late May and has produced a 2.70 ERA, 1.40 WHIP and 16:6 K:BB in 10 innings across 10 relief appearances.