BOSTON — The Yankees have to sit on their dud from Friday night a little while longer.

Their game on Saturday night against the Red Sox was postponed by rain, which was expected to continue throughout the evening at Fenway Park.

The result will be a split doubleheader on Sunday, with Game 1 scheduled to begin at 1:35 p.m. and the nightcap starting at 7:10 p.m.

Clarke Schmidt will start Game 1 for the Yankees against a Red Sox pitcher to be announced before Luis Severino and Brayan Bello square off on ESPN’s “Sunday Night Baseball.”

The Red Sox were hoping to get the game in Saturday despite the forecast, but it was finally called shortly before 5 p.m., which the Yankees seemed to expect since they never released a lineup for the game.

“Better than waiting till 7 or 8 o’clock,” manager Aaron Boone said.

Because of the postponement, the Yankees will need a fifth starter by their game Wednesday against the Mariners.

They had been taking advantage of days off to use a four-man rotation because Nestor Cortes is on the injured list, and they were originally not scheduled to need a fifth starter until next Saturday.

Now that will be bumped up a few days, with Randy Vasquez and Jhony Brito the potential call-up options.

Both last pitched on Thursday for Triple-A Scranton/Wilkes-Barre, so they would be on regular rest for Wednesday.

Harrison Bader (strained hamstring), after playing in another rehab game for Double-A Somerset, texted Boone on Friday night and said that he “felt really good.”

The center fielder went 1-for-4 in Somerset’s 8-1 win over Altoona on Saturday night and is now potentially ready to rejoin the Yankees on Tuesday in The Bronx.

Matt Krook’s MLB debut on Friday did not go how he had hoped, but it was a long time coming.

The Yankees first called up the 28-year-old reliever on May 27, before sending him back to Triple-A on June 1 without needing him to pitch.

They called him up again on June 8 and he watched seven games from the bullpen before finally getting the call in the third inning Friday.

The left-hander, who did not get much help behind him, gave up five runs over 1 ²/₃ innings in relief of Domingo German. But he did cherish the opportunity.

“I’m just super grateful for the opportunity,” Krook said. “Worked a long time to get here, so it means a lot. It was Yankees-Red Sox, Friday night, a lot of fun. But wish the outcome [was different].”