Miami will be at Washington for four games (Sept. 17-20). Fernandez should be lined up for either the first or second game of that series, depending on if the Marlins schedule him to next pitch on the fifth or sixth day.
The Nationals already have an uphill climb to catch the Mets in the National League East. Now, they run the likelihood of seeing one of the top young right-handers in the game.
"They're in a battle," Miami manager Dan Jennings said. "So I'm sure they're ready on whoever goes out there, they've got to step up to play."
Fernandez hasn't pitched since Aug. 7 at Atlanta, experiencing tightness in his shoulder area after a five-inning, six-strikeout outing.
Fernandez threw a simulated game on Monday at Marlins Park, and on Wednesday had a bullpen session.
"He threw the ball very well, getting in line for Saturday," Jennings said. "So it looks like all systems are go there, for him to get ready to toe the rubber and pitch against the Nationals.
"Every step along the way is a test. Once he passes one test, he moves to the next. He's passed this one, the next one will be Saturday against the Nats."
The Marlins also received encouraging news with reliever Carter Capps, who has been on the disabled list since Aug. 3 with a right elbow strain.
Capps threw off the mound without any discomfort on Wednesday.
"He threw flat ground today, it was good," Jennings said. "He looks very good. I think we're probably one bullpen away and then we'll make a decision. Right now, he feels strong. The ball is coming out of his hand very well. So it could be sooner rather than later."
Best case scenario, Capps could be reinstated for the road trip, which begins on Monday at the Mets.
• The Marlins are not expected to activate first baseman/outfielder Tommy Medica, claimed off waivers from the Padres on Tuesday. The 27-year-old has options, and should get a look in Spring Training. He had five homers and 39 RBIs in Triple-A this season, and has 57 homers in 424 career Minor League games.