Forrest Whitley began 2018 as one of the best pitching prospects in baseball and figured to end his season by helping the Astros try to win another World Series. Instead, he wound up in the Arizona Fall League.

Similarly, Whitley started 2019 as one of the best pitching prospects in baseball and looked like a lock to participate in Houston's postseason. And yet, he's back in the Fall League.

Just as he did last autumn, he's determined to make the best of his AFL assignment.

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"The year didn't go the way that I had planned it," said Whitley, who battled shoulder fatigue and command issues while posting a combined 7.99 ERA with 86 strikeouts and 44 walks in 59 2/3 innings at four different levels of the Astros' system. "Out of the crop of guys I played with last year, I would have thought I would have been one of the first guys up.

"But baseball is a humbling game. It's the way that it goes and I just [have] to adapt to the position I'm in right now. I just need to come out and have a strong Fall League to propel me to 2020."

Whitley -- the No. 17 overall pick in the 2016 Draft and currently ranked by MLB Pipeline as No. 17 among its Top 100 Prospects and as Houston's No. 2 prospect -- began his 2019 season by getting knocked around for a 12.21 ERA in eight Triple-A outings, and then he missed seven weeks with shoulder fatigue. The quality of his stuff fluctuated at times throughout the year, though few pitchers can match his repertoire when he's in his groove. He can show a 93-98 mph fastball with natural cut and sink, a pair of power breaking balls in a 12-6 curveball and late-breaking slider, plus a devastating changeup that fades and dives.

Whitley attributes a lot of his woes to trying to make some necessary mechanical changes. After his shoulder started bothering him, he concentrated on maintaining a better posture in his upper body and he's still getting used to the difference. While learning a different delivery has compromised the quality of his pitches and his ability to locate them in the short term, he said it will make him better and healthier in the long run.

"I'm getting a lot more comfortable with the newer delivery, throwing a lot more strikes as of late, bullpen [sessions] have been really solid lately," said Whitley, who turned 22 three days before the Fall League season began. "I like the direction I'm going with the new delivery and I think it will benefit me going forward."

Whitley's season followed a 2018 campaign that also didn't go as planned. He missed the start with a 50-game suspension for violating the Minor League drug program, then later he lost time to minor oblique and lat injuries and he ended up throwing just 26 1/3 innings. He then dominated in the AFL for the Scottsdale Scorpions, leading the league with 36 strikeouts and recording a 2.42 ERA (fourth among starters) in 26 innings.

Now pitching for the Peoria Javelinas, Whitley starred in his first AFL outing of 2019. He took a no-hitter into the fifth inning on Saturday against the Mesa Solar Sox and finished with six strikeouts and just one hit allowed in 4 2/3 frames, a good start toward generating momentum he can carry into next year.

"It stinks that I'm not [with Houston] right now enjoying the playoff run with one of the most historically good teams of all time," Whitley said. "It's a tough feeling but it's also a good opportunity to know that you're still in a good position, even next year, to be on that team and a part of what's going on up there. I'm just really excited for the opportunity and what's to come in 2020."

Astros hitters in the Fall League

Jeremy Peña, SS/2B (Houston's No. 9 prospect) -- The son of former big leaguer Gerónimo Peña, Jeremy was a third-round Draft pick out of the University of Maine in 2018. Known more for his slick defensive skills as a college player, he hit better than expected in his first full pro season, batting .303/.385/.440 with seven homers and 20 stolen bases in 109 games at Class A Quad Cities and Class A Advanced Fayetteville.

J.J. Matijevic, 1B/OF (No. 18 prospect) -- A 2017 second-round Draft pick from the University of Arizona, Matijevic has shown the ability to hit for power or average at various points in his career and he is now trying to find a happy medium as well as a defensive home. He batted .251/.319/.441 with 11 homers in 78 games (mostly at Double-A Corpus Christi) this year after serving a 50-game suspension for a second positive test for a drug of abuse.

Colton Shaver, 3B/C/1B -- Shaver hit 36 homers in three years at Brigham Young University and his power got him drafted in the 39th round in 2017. He hit .248/.361/.481 with 21 homers in 113 games at Fayetteville and Corpus Christi in 2019 before Houston sent him to the AFL to develop his catching ability, which remains raw.

Astros pitchers in the Fall League

Cody Deason, RHP -- A college teammate of Matijevic's at Arizona, Deason was selected in the fifth round of the 2018 Draft. Employing an 89-93 mph fastball with riding action and a curveball with impressive depth, he logged a 3.40 ERA with 120 strikeouts in 100 2/3 innings at Quad Cities and Fayetteville in his first full pro season.

Carlos Sanabria, RHP -- Signed for a mere $7,000 out of Venezuela in 2014, Sanabria has blossomed into a reliever with a mid-90s fastball that touches 98 mph and power breaking stuff, though his control and command are still works in progress. He recorded a 2.84 ERA, .176 opponent average and 86 strikeouts in 66 2/3 innings at Fayetteville and Corpus Christi in 2019.

Jojanse Torres, RHP -- A late bloomer who signed out of the Dominican Republic in April 2018 -- more than six years after he first became eligible -- Torres has a 95-98 mph fastball that reaches triple digits and a slider that can hit 90 mph. He went 12-0 with a 1.71 ERA, .175 opponent average and 107 strikeouts in 94 2/3 innings at Quad Cities and Fayetteville this season.