HOUSTON -- The Houston Astros and Philadelphia Phillies made only minor changes from their championship series rosters for their World Series rosters ahead of Game 1 on Friday night.

Houston added left-hander reliever Will Smith, who was left off the roster for the first two rounds of the playoffs. The 33-year-old Smith was acquired in a trade with the Braves this summer, was in seven playoff series and helped Atlanta to a World Series win over the Astros last season.

Houston took right-hander Seth Martinez, who did not pitch in the American League Championship Series, off the roster to make room for Smith.

The Phillies added utility player Nick Maton and reliever Nick Nelson to the roster and took utility player Dalton Guthrie and right-hander Bailey Falter off.

Maton was on the wild-card roster but did not play in the series against St. Louis. The left-handed hitter is the brother of Houston reliever Phil Maton, who is out for the season after breaking a pinkie finger punching a locker after giving up a hit to his brother in the team's regular-season finale.

Guthrie took Maton's place on the National League Division Series and NLCS rosters but had only one appearance as a pinch runner against the Braves in the division series.

Nelson was on the NLDS roster but did not appear in a game.

Falter started Game 4 of the NLCS, giving up three hits and four runs in two-thirds of an inning in his postseason debut.

Houston's roster has 13 pitchers, two catchers, eight infielders and three outfielders.

The Phillies have 13 pitchers, two catchers, six infielders and five outfielders.