The Marlins and Nats will conclude their series with Wednesday's regularly scheduled game in D.C. (AP)

WASHINGTON -- About the time the Marlins were wrapping up batting practice at Nationals Park on Tuesday night, the grounds crew was rolling the tarp onto the field in anticipation of heavy rains.

About an hour later, roughly at 7:15 p.m. ET, the Marlins-Nationals game was postponed.

Marlins manager Mike Redmond said the game will be made up as part of a doubleheader during the club's final visit to Washington, which is the weekend of Sept. 26-28.

A tentative date, Redmond said, was Friday, Sept. 26, as part of a day/night doubleheader. No official rescheduling has been announced.

"Not ideal," Redmond said. "An ideal situation for us is to play, obviously. Nobody likes to play doubleheaders, especially late in the season. The only good thing is you have more players to cover it."

Because of September callups, teams have more players to use in the final month.

As for now, the Marlins were hopeful to get the game in on Tuesday. The series wraps up on Wednesday at 7:05 p.m. ET. However, rain is in the forecast. But with both teams off on Thursday, it appears all sides are willing to wait as long as possible to get the game in.

Redmond added that the Nationals determine the makeup day. Playing a doubleheader on Wednesday or perhaps making Tuesday's game up on Thursday was not seriously discussed.

Tuesday's postponement shakes up Miami's rotation over the next few days.

Henderson Alvarez, Tuesday's scheduled starter, will now pitch on Wednesday in place of Tom Koehler, who is being pushed back to start on Friday at home against the Braves.

Jacob Turner has been pushed back to throw on Saturday, and Nathan Eovaldi will stay on schedule and face Atlanta on Sunday.

Randy Wolf was initially scheduled to start on Sunday.

Redmond said Wolf will pitch either Monday or Tuesday in Miami.

The Nationals, meanwhile, were set to start Blake Treinen on Tuesday. On Wednesday, Washington will stay with its originally scheduled starter, Jordan Zimmermann.

The Marlins won the series opener on Monday, 3-2.

Miami is in second place in the National League East with a 27-25 record, while the Nationals are sitting at 25-26.

Both clubs are primed to be in the race for the long haul. Now, they have the doubleheader on tap in the final weekend of the season.

"If you're in the race, or you have a chance, nobody wants to be playing doubleheaders that late," Redmond said.

Being able to play on Tuesday wasn't an issue.

The Marlins were taking batting practice under threatening skies.

"We heard the radar was going to be bad all night," first baseman Garrett Jones said. "The grounds crew was out there during BP. We were kind anticipating. It was just one of those things where it didn't look like it was going to let up all night. Bang it early, and get them tomorrow."