Astros Reluctant To Part With Francis Martes

HOUSTON—A rotation headlined by two pitchers coming off injuries is the biggest question mark the Astros face in 2017.

General manager Jeff Luhnow has the prospect capital necessary to deal for an upgrade, but what if the prospect coveted most in trade discussions is also a potential answer to their starting-pitching questions?

This is the risk the Astros would face if they parted with 21-year-old righthander Francis Martes, who not only is the organization’s No. 1 prospect but also among its closest to the majors. Though he is far from a finished product, the hard-throwing Dominican is expected to debut at some point in 2017.

“Francis Martes is getting close,” Luhnow said, “and I could see him following the Lance McCullers Jr. path of starting in either Double-A or Triple-A, and somewhere in the middle of the season getting a callup to the big leagues.

“He’s got the weapons to get big league hitters out right now. It’s just a matter of a little more seasoning.”

McCullers began the 2015 season at Double-A Corpus Christi but made just six appearances before he was summoned to Houston in mid-May. Just 21 years old at the time, he emerged as one of the Astros’ best pitchers and started a playoff game against the Royals that fall.

Martes is probably ticketed for Triple-A Fresno in 2017. He spent all of last season in Double-A, where he recovered from a poor April to finish with a 3.30 ERA in 125 innings. His development continued in the Arizona Fall League.

The Astros acquired Martes (and others) from the Marlins at the 2014 trade deadline when they shipped Jarred Cosart (and others) to Miami.

Martes, whose stocky 6-foot-1, 225-pound build has elicited comparisons with a young Johnny Cueto, used his time in the AFL to work on his changeup, which is far and away his third pitch behind his mid-90s fastball and power slider.

The development of Martes’ changeup and how he fares against advanced Pacific Coast League competition will help dictate when he reaches the big leagues.

SPACE SHOTS

• Luhnow acknowledged righthander Michael Feliz “more than likely” will remain in the bullpen. He started in the minors and could return to that role in the future.

• The Astros added lefthanded relief depth with the Dec. 5 waiver claim of 28-year-old Ashur Tolliver from the Angels.

— Jake Kaplan covers the Astros for the Houston Chronicle