HOUSTON -- Rookie right-hander Hunter Brown, the team¡¯s top-ranked prospect by MLB Pipeline, was one of 12 pitchers the Astros will carry on their roster for the American League Division Series against the Mariners.

Veteran relievers Phil Maton and Will Smith, a lefty who helped the Braves win the World Series last year, were left off the roster. In addition to Brown, another rookie -- infielder David Hensley -- made the roster as well. Brown and Hensley are two of seven players with no postseason playing experience. Infielder Mauricio Dub¨®n, infielder/outfielder Trey Mancini, right-handers Rafael Montero and Hector Neris and shortstop Jeremy Pe?a are the others.

The Astros won¡¯t carry any left-handers in their bullpen against a Mariners lineup that includes left-handed bats Adam Frazier, Jesse Winker, Jarred Kelenic and J.P. Crawford. Houston has some versatility with its position players, as Aledmys D¨ªaz and Hensley can play the infield and the outfield and Mancini can play left field and first base.

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Here is the 26-man roster:

Pitchers (12): Right-handers Bryan Abreu, Hunter Brown, Luis Garcia, Cristian Javier, Lance McCullers Jr., Rafael Montero, H¨¦ctor Neris, Ryan Pressly, Ryne Stanek, Jos¨¦ Urquidy and Justin Verlander; left-hander Framber Valdez

Catchers (2): Mart¨ªn Maldonado and Christian V¨¢zquez

Infielders (8): Jose Altuve, Alex Bregman, Aledmys D¨ªaz, Mauricio Dub¨®n, Yuli Gurriel, David Hensley, Trey Mancini and Jeremy Pe?a

Outfielders (4): Jake Meyers, Yordan Alvarez, Chas McCormick and Kyle Tucker