The bullpen returns intact from last year, and the starting rotation enters camp with six starting pitchers -- Dallas Keuchel, Collin McHugh, Lance McCullers, Mike Fiers, Charlie Morton and Joe Musgrove -- and five slots. So who is best-positioned to surprise this spring?
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It's a stretch to see hard-throwing Francis Martes making the club out of camp, but a solid showing in front of the Major League staff could position him to make his big league debut at some point this season -- at 21 years old.
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Martes, the Astros' No. 1 prospect and No. 20 overall by MLBPipeline.com, spent all of 2016 in the rotation at Double-A Corpus Christi. He struck out 131 and walked 47 batters in 125 1/3 innings, going 9-6 with a 3.30 ERA as the youngest pitcher (20 years old) in the Texas League.
"I think he's intriguing because of how well he's performed as he's raced through the Minor Leagues," Astros manager A.J. Hinch said. "He's young for the levels he's played at, he's been intriguing with his skillsets and had a nice showing in the [Arizona] Fall League.
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"He's answered every challenge at a young age. Never say never. When you have the luxury to be able to develop him at the pace he's helping dictate, he's a guy I'll have my eyes on up close and personal... [to] see how he responds being in his first big league camp and around older players."
Martes was throwing in the upper 80s when he was signed by the Marlins out of the Dominican Republic in 2012, and the Astros plucked him away from Miami midway through the '14 season in the trade that sent Jarred Cosart to the Marlins. He now sits in the mid-90s and touches 98, with a good curveball.
Barring injuries, Martes is likely to begin the season at Triple-A Fresno, putting him in position to make his debut this year. The Astros haven't been shy about pushing top prospects in the past couple of years, with McCullers and Michael Feliz making their debuts in 2015 despite not throwing a pitch a Triple-A. Prospect David Paulino made his debut in '16 after only three games at Triple-A, and Chris Devenski had worked in only one game above Triple-A.
The Astros, of course, have been in the market for another starting pitcher all offseason, which could delay Martes' timeline. Houston has been reluctant to move third baseman Alex Bregman and top position-player prospect Kyle Tucker (OF) along with Martes. If the Astros are bent on keeping Martes, that's a sign they believe he could be big league ready sooner rather than later.
Astros pitchers and catchers are scheduled to report on Feb. 14, with the full squad scheduled to report Feb. 18.