First pitch for Game 4 will be 8:08 p.m. ET Thursday. Game 5 has been rescheduled for 7:08 p.m. ET Friday, which originally had been tabbed as a travel day, if necessary.
"It gives everybody a day off and an opportunity to collect ourselves," Astros manager A.J. Hinch said. "It changes our pitching a little bit; how beneficial is probably easier to answer after I see how guys perform and how the pitching plays out."
The Yankees -- who were planning a bullpen day for Game 4 -- have announced they will go back to Masahiro Tanaka on regular rest. He blanked the Astros over six innings in Game 1 on Saturday, throwing just 68 pitches during a 7-0 win.
The Astros will counter with Zack Greinke, also on regular rest. The 2009 Cy Young Award winner, who was acquired from Arizona at the July 31 trade deadline, has struggled through two starts for the Astros this postseason, including the Game 1 loss to the Yankees in which he allowed two homers and three runs in six innings.
The Astros have a 2-1 lead in the best-of-seven series. The winner will face the Washington Nationals in the World Series.
Having Wednesday off will be welcome for New York after manager Aaron Boone used five relievers to cover 4 2/3 innings in Tuesday's 4-1 loss to the Astros. Starter Luis Severino threw 36 pitches in the first inning and was pulled in the fifth. Boone deployed key arms Chad Green, Tommy Kahnle, Adam Ottavino and Zack Britton in the loss, although none threw more than 11 pitches.
Games 6 and 7, if necessary, are not affected by Wednesday's postponement and will be held in Houston on Saturday and Sunday.
Wednesday's matchup is the first postseason game to be postponed since Game 4 of the National League Division Series between the Nationals and the Chicago Cubs in 2017, and the first LCS game to be called off since Game 3 of the Baltimore Orioles-Kansas City Royals series in 2014.
The Associated Press contributed to this report.