It was the second cancelled game for the Marlins in six days. On Saturday, they got two innings in against the Tigers before play was halted.
David Phelps was scheduled to start for Miami on Friday. Instead, the right-hander threw 70 pitches in the bullpen.
Friday's washout doesn't change the club's pitching plans for the next few days. Wei-Yin Chen, already announced as the Opening Day starter, will face the Astros on Saturday at 6:05 ET in Kissimmee. On Sunday, Jose Fernandez, who will start the second game of the season, will face the Cardinals at 1:05 p.m. ET at Roger Dean Stadium.
The Marlins were planning to go with a majority of their regulars against the Nationals, who also brought most of their top players on the trip.
Dee Gordon, Marcell Ozuna, Christian Yelich, Giancarlo Stanton, Justin Bour, Martin Prado, Adeiny Hechavarria and Jeff Mathis were set to start.
Scheduled to make the trip on Saturday are Gordon, Ozuna, Chris Johnson, Bour, Cole Gillespie, Derek Dietrich, J.T. Realmuto and Miguel Rojas.
Also on Saturday, right-hander Jarred Cosart, the likely No. 5 starter, will pitch in a Minor League game at 1 p.m. ET on a back field at Roger Dean Stadium.
Phelps is in the mix as either a starter or a bullpen role. Even if he isn't in the rotation on Opening Day, he is being built up to pitch multiple innings. In each of the past two seasons, the Marlins have used 13 starters, so depth is essential.
"We're still working guys toward the end," manager Don Mattingly said. "[Phelps] threw the ball well his last time out. He's really valuable because he can go from the bullpen to the starting rotation. Certain guys can't do that. We want to build him up so he is capable of doing either one."