This Astros' RHP prospect is making noise in Double-A

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HOUSTON -- The Astros haven’t developed many relievers in recent years, save for Bryan Abreu and Logan VanWey and even now Forrest Whitley, who was taken in the first round of the 2016 Draft as a starter before injuries and underperformance sent him to the bullpen prior to last season.

One of the biggest power arms in the system is right-hander Alimber Santa, a reliever who could push his way onto the radar soon. Santa appeared in eight games for Double-A Corpus Christi in April and allowed two earned runs in 15 2/3 innings (1.15 ERA), with 12 hits, two walks and 12 strikeouts. He had a 0.89 WHIP and .222 batting average against.

Santa's fastball sat at 88-91 mph when he signed out of the Dominican Republic in February 2020, but he was limited to just 23 innings in his first two professional seasons due to the pandemic shutdown and elbow inflammation.

While Santa lacks physicality, he has a lightning-quick arm that unleashes riding fastballs that sit at 94-96 mph and repeatedly touch 97-98. He has a tight slider that reaches the upper 80s, a sweepier mid-80s version and an upper-70s curveball with more depth.

“The mix of the three weapons, he’s got something he can throw to both bat sides between those three pitches,” said Astros senior director of player development and performance science Jacob Buffa. “I think the velo on the breakers just makes him really difficult to hit.”

Santa came to the United States about the same time as fellow right-hander Miguel Ullola, but Santa’s injuries allowed Ullola to progress a little quicker. Buffa said Santa’s ceiling would be comparable to Abreu, which would be a good result for the Astros.

The Astros have Santa on a “hybrid” setup, which means he throws two or three innings twice a week.

“We’re not huge fans of turning guys into straight relievers early in the Minor Leagues because mainly it limits [developmental] reps if you throw two innings in a week,” Buffa said. “It’s difficult to get the reps in that you need to develop. We have him basically going one time through the lineup and trying to throw him twice in a week.”

What will allow Santa to take the leap to the next level, and beyond, is getting in the strike zone consistently with his breaking pitches.

“This game has evolved to such a way that, when you’re in a 2-0 count, you can no longer afford to let the hitter know a fastball is coming,” Buffa said. “That’s probably where his last hurdle is. What’s his alternate strike pitch, something he can land as a non-fastball?”

Here’s a look around the rest of the system:

Triple-A Sugar Land
Ullola, the Astros’ No. 5-ranked prospect (per MLB Pipeline) tied the longest outing of his career Thursday in a 3-0 win over Round Rock. Ullola threw five innings and struck out five batters while allowing one hit and no earned runs. He has a 6.00 ERA in 15 innings pitched this season, allowing 10 walks while striking out 16 batters.

“We’re extremely happy with what we’ve seen,” Buffa said. “It’s been a big step forward for him. I think he’s lucky to be in this scenario of understanding how good his stuff is and understanding that he’s good enough to beat hitters in the zone. At times, he had tried to get too fine [and say] ‘I’ve got to hit the corner, I’ve got to hit the corner.’ When in reality, the stuff is so good he just has to be in the zone generally.”

High-A Asheville
Center fielder Joseph Sullivan (the team’s No. 12-ranked prospect) has shown a fantastic approach at the plate and elite bat-to-ball skills so far this year, with 26 walks and five homers in 98 plate appearances. The 26.5 percent walk rate probably isn’t sustainable for the rest of the year, but it’s a positive sign for the Astros that he’s not chasing pitches.

“That combination from someone who’s [22] years old of not chasing and hitting the ball hard is extremely exciting, plus he can play center-field defense,” Buffa said.

Single-A Fayetteville
Right-hander pitcher Bryce Mayer, 23, has a 2.51 ERA with 27 strikeouts, two walks, a 0.84 WHIP and a .192 opponents’ batting average in four appearances (including two starts) in April. The team’s No. 29 prospect, Mayer was drafted in the 16th round last year out of Missouri.

“He’s got a [46.6] percent K-rate against both bat sides on the season and hasn’t walked a righty yet,” Buffa said. “He’s just mowing through guys down there right now.”