The postponement took place on Jackie Robinson Day across the majors, and in the aftermath of Jacob Blake, 29, a black man, shot dead by police in Wisconsin over the weekend.
All Minute Maid Park players, managers and coaches wore the number 42, the jersey Robinson wore when he broke the major league color barrier in 1947.
The Athletics and Astros placed a No. 42 jersey in each batter’s box. The Houston starters took up their positions, with other players from both sides lined up in front of their shelters.
After a moment of silence, the teams returned to their clubs.
There have been 11 league games postponed this week as clubs joined teams from the NBA, WNBA and MLS to cancel games while protesting social injustice.
Major League Baseball lets teams decide whether or not to play.
No makeup date was immediately announced for the A’s-Astros game.
Astros manager Dusty Baker and track and field manager Bob Melvin met the umpires at home plate several minutes before the scheduled opening pitch at 8:10 p.m.
Oakland starter Chris Bassitt appeared to be going through his pre-game routine, preparing to throw into the visitor’s paddock, but abruptly stopped warming up about 15 minutes before the scheduled first pitch.
Houston starter Lance McCullers Jr. walked to the right-field pickup pen with a glove and orange ball, but only sat on a bench and never warmed up before returning to the field. shelter shortly after the national anthem.
On Thursday, the New York Mets and Miami Marlins took similar action ahead of their game at Citi Field.