Heavy rain fell Wednesday and washed away the Astros’ plan for a bullpen day.

Zack Greinke and Justin Verlander are the thunder and lightning to follow.

After Game 4 of the ALCS was postponed Wednesday, Astros manager A.J. Hinch made what he called the “very easy” decision to bump up Greinke and Verlander to start Thursday and Friday at Yankee Stadium, with a 2-1 series lead in hand.

“As soon as we can use our best pitchers, the better for us,” Hinch said Wednesday on a conference call.

Greinke was going to start Thursday regardless, Hinch said, and will match up with Masahiro Tanaka. Verlander will be on regular rest Friday in Game 5, likely against James Paxton. Should the Yankees force a Game 6 on Saturday in Houston, the Astros could opt for a bullpen game or go back to the red-hot Gerrit Cole on short rest.

Through three games, the Astros’ big three of Cole, Verlander and Greinke have been responsible for pitching 19 2/3 of the 29 innings. They have spotted the Yankees just five runs on 16 hits and seven walks while largely preserving their top bullpen arms for a potential four games in four days — if the series gets that far.

“We’re here to win, and win as fast as we can,” Hinch said.

“We’d like to do it here,” outfielder Josh Reddick said after a 4-1 win in Game 3 at Yankee Stadium, and that was before knowing the Astros would have the luxury of skipping their bullpen day.

The last time Greinke pitched at Yankee Stadium, on July 31, he gave up two runs in five innings for the Diamondbacks and then got traded to the Astros during a rain delay. Greinke took the loss in Game 1 against the Yankees, giving up home runs to Gleyber Torres and Giancarlo Stanton while allowing three runs over six innings.

In Greinke’s two playoff starts this month, he has given up five home runs in 9 2/3 innings, but Hinch was not overly concerned about the trend.

“The first [start] he was on 10 or 11 days’ rest. I don’t think he had his best secondary pitches,” Hinch said. “And then the other day against the Yankees, that was really the only damage they did were the home runs, which this team — it’s one of their strengths.

“I think for him, execution is always key. He’s one of the best at it when he gets locked in with his mechanics and timing and delivery. He makes his pitches when he makes his pitches and he’s really, really difficult to hit. And you can see that just based on how good he is for as long as he’s been good.”