WEST PALM BEACH, Fla. -- The Astros are loaded with pitching prospects. Forrest Whitley ranks as the best in baseball, and Josh James, Corbin Martin and J.B. Bukauskas join him as MLB Pipeline Top 100 Prospects who will be ready to contribute in Houston at some point in 2019.

Right-hander Bryan Abreu isn't nearly as hyped or advanced, but he has comparable stuff. Though he has totaled just 38 1/3 innings in full-season ball in five years as a pro, the Astros protected him on their 40-man roster in November rather than risk losing him in the Rule 5 Draft.

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Getting added to the roster meant that Abreu participated in big league Spring Training for the first time. Though he gave up six runs in three innings in three appearances before getting sent to Minor League camp, he said it will help in his development.

"It was really good, a lot of experience and a different environment," said Abreu, who signed for $40,000 out of the Dominican Republic in 2013. "A lot of advice and just learning a lot of things. I was kind of quiet and I asked some specific things and tried to learn."

Abreu tried to pick up on the work habits of the members of Houston's pitching staff. The importance of not rushing his delivery was reinforced after he had trouble commanding his pitches. Nevertheless, he made an impression on Astros manager AJ Hinch, who described both Abreu's curveball and slider as plus offerings.

Members of Houston's player development staff will go even further, with some likening Abreu's curveball to the absolute hammer that Lance McCullers Jr. possesses. He generates huge spin rates and tremendous depth on his low-80s curve, and he said he actually has more trust in an upper-80s slider that he tightened last season with the help of pitching coach Graham Johnson at Class A Quad Cities.

Abreu's breaking balls destroyed right-handed hitters last season, as he held them to a .380 OPS while striking out 52 percent of them. He posted a 1.49 ERA with 90 strikeouts in 54 1/3 innings between short-season Tri-City and Quad Cities.

"He has tremendous arm speed," Astros farm director Pete Putila said. "He's not sacrificing anything with either breaking ball -- there's intent with both. They're pretty close. He's always had a curveball and now the slider is a weapon that he's able to execute consistently."

Abreu's fastball is difficult to contend with as well, ranging from 92-96 mph with running action. His biggest needs at this point are to refine his circle changeup and continue to improve his control and command. He did a better job of locating his pitches in 2018, cutting his walk rate to 3.8 per nine innings after averaging 6.2 in his first four pro seasons.

Abreu said the lowest moment of his career provided the impetus for his breakout last year. He injured his elbow in August 2017 after recording his worst ERA as a pro (7.98) at Rookie-level Greeneville. After rehabbing back home in the Dominican Republic, he said he improved physically and mentally.

"I was stronger and my mind was changing completely," Abreu said. "I just trusted myself and tried to do everything the right way. It was so perfect how I felt last year."