Astros hoping this prospect could be their next key reliever

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HOUSTON – The Astros placed right-hander Miguel Ullola, the team’s No. 11 prospect according to MLB Pipeline, on the 40-man roster last November, which came with an invite to Major League camp and a chance to show the staff he was ready to compete for a spot in Houston’s rotation in 2026.

The pitching depth added by the Astros last offseason -- they traded for starters Mike Burrows and Kai-Wei Teng and signed Peter Lambert and Ryan Weiss -- created more competition for Ullola, whose inability to consistently throw strikes was his final hurdle to reach the big leagues for the first time.

Ullola has a 6.20 walks per nine innings ratio in his Minor League career, but an 11.99 strikeouts per nine innings ratio, which makes him somewhat of an enigma. With that in mind, the Astros made the decision late last month to convert him to a reliever, with hopes his exceptional fastball could be a bigger weapon in shorter outings.

“See if we can get him in the zone more as a reliever,” Astros manager Joe Espada said. “The stuff will play up more, so we kind of kicked the tires. Obviously, he’s got to throw strikes. I do like him as a starter. But we always talk about if the quality of pitches is not there for 80 pitches, can we make it quality for 30 or 35? And you start narrowing it down when they get to Triple-A. He’s started [86] games already, so now we start getting a better feel for what he’s going to be and how can impact our roster.”

Ullola had a 6.56 ERA and 1.68 WHIP in his first nine starts this season for Sugar Land before throwing two scoreless innings May 26 as an opener. In his first relief appearance Saturday, he threw eight of 11 pitches for strikes, averaged 95.9 mph on his fastball and touched 97.3 mph, the hardest pitch of his career. He pitched in relief again Tuesday and was scoreless again.

“He's been shortened down,” Astros director of player development Sam Niedorf said. “He opened one game a week ago and the past two have been straight relief, but the stuff’s kicked up a little bit. The intent’s kicked up, which has been exciting. I’m excited to see where he goes from here.”

Ullola, who turned pro for $75,000 out of the Dominican Republic at age 18 in 2021, has one of the most unhittable fastballs in the Minors, even though it sits at 92-94 mph and tops out at 97.

“The past two outings have been really encouraging,” Niedorf said. “It's been 55% in zone both times, which is a step up from where he was as a starter. So I think, again, shorten him down, not having him face the lineup two or three times, has been really, really positive for him. Just simplifying the game as much as we can to make him the best option possible for the Major League club.”

The Astros promoted No. 16 prospect Alimber Santa to the Major League club last week and he retired the first 18 batters he faced. The team’s bullpen performed much better in May (3.27 ERA) than they did in April (7.14 ERA), and All-Star closer Josh Hader returned from the injured list this week.

Still, the struggles of setup man Bryan Abreu (7.91 ERA) have left the Astros without an effective back-end reliever they’d been counting on and Ulloa could help fill that void later in the season. The Astros’ bullpen entered Wednesday with the third-most walks in MLB.

“We don’t want him to come up here and struggle,” Espada said. “We want to put him in a position where he has success. This stuff is good. Just have to get him in the zone consistently.”