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The Houston Astros and Philadelphia Phillies on Friday announced their rosters in advance of Game 1 of the World Series. The Astros made one change to their LCS roster, while the Phillies made two. 

In Houston's case, lefty reliever Will Smith has been added, and right-handed reliever Seth Martinez has been left off. Smith, 33, was acquired from the Atlanta Braves in exchange for Jake Odorizzi leading up to this year's trade deadline. In 22 innings for Houston this season, he pitched to a 3.27 ERA and a 6.00 K/BB ratio. Smith no doubt has been added to the roster so that Astros manager Dusty Baker has another means to parry Bryce Harper and Kyle Schwarber -- the Phillies' two best hitters who also happen to bat left-handed. Speaking of which: 

Here's the Astros' full World Series roster: 

As for Philly, lefty Bailey Falter, who made one very brief and very unsuccessful start against the Padres in the NLCS, has been left off the World Series roster as has utility man Dalton Guthrie. Guthrie was on the Phillies' roster for the Wild Card Series, NLDS, and NLCS, but he made only appearance, which came as a late-inning pinch runner and then defensive replacement against the Braves in NLDS Game 3. 

New to the roster for the Phillies are utility man Nick Maton, who bats lefty, and right-handed reliever Nick Nelson. Nelson during the regular season logged a 4.85 ERA and 1.92 K/BB ratio in 68 2/3 innings. Those results weren't optimal, but Nelson does give the Phillies big fastball velocity, which they'll likely need more of against Houston. 

Here's the Phillies' full World Series roster: 

First pitch of Game 1 in Houston is scheduled for 8:03 p.m. ET on Friday night.