The Astros are expected to recall Ullola from Triple-A Sugar Land prior to Sunday's game against the Tigers, Chandler Rome of The Athletic reports.
Houston has already optioned right-hander Kai-Wei Teng to Triple-A to open up room on the 26-man active roster for Ullola, who is set to receive his first big-league call-up.The 24-year-old has posted a 5.48 ERA, 1.55 WHIP and 64:35 K:BB in 47.2 innings over 20 total appearances with Sugar Land this season, but he pitched more effectively after making the full-time move to the bullpen in late May, turning in a 2.70 ERA and 16:6 K:BB across 10 frames. Ullola is likely to serve as a low-leverage reliever while he's up with Houston.