"I don't know how hard he was throwing," Marlins manager Mike Redmond said about Eovaldi. "They don't have a radar gun here. Usually you can tell by the reactions of the hitters. There were not a lot of comfortable swings in there. That's usually a good sign."
Right-hander Dan Haren pitched his first game for the Nationals and was solid, but he got off to a slow start in the first inning.
Christian Yelich led off with a triple and then scored on a sacrifice fly by Donovan Solano to give the Marlins a 1-0 lead. Matt Downs followed with a single to left field before Joe Mahoney reached base on an error by Haren to put runners on first and second. But Haren managed to get out of the inning when Alfredo Silverio grounded out to third baseman Chad Tracy and Chris Coghlan struck out.
Haren pitched two innings, allowing the one run on two hits and struck out three batters.
The Marlins scored their second run against reliever Tanner Roark in the sixth inning, when Solano scored on a single by Coghlan. Roark allowed three more runs in the following frame. Derek Dietrich had an RBI double, while Ed Lucas had a two-run single.
The Marlins' pitchers proved to be too much for the Nationals, who struck out 10 times in the game. Steve Lombardozzi and Danny Espinosa collected the first two of three Nationals hits on the afternoon.
The Nationals managed to score in the bottom of the eighth inning. With the bases loaded, one out and left-hander Braulio Lara on the mound, Carlos Rivero hit a sacrifice fly, scoring Matt Skole.
Up next: Jacob Turner, competing for a top-of-the-rotation spot, makes his first Grapefruit League start. The right-hander will face the Cardinals as the road team on Thursday at 1:05 p.m. ET at Roger Dean Stadium. Jake Westbrook will start for the Cardinals. Giancarlo Stanton, Juan Pierre, Placido Polanco and Rob Brantly are among the regulars expected to start.
Bill Ladson is a reporter for MLB.com and writes an MLBlog, All Nats All the time. He also could be found on Twitter @WashingNats. This story was not subject to the approval of Major League Baseball or its clubs.