Manager Matt Williams again says the team is not concerned about the right-hander's barking right elbow.
Ross Detwiler starts the home game against the Braves and Chris Young starts the away game against the Cardinals.
The catcher hit a wind-aided ball so far it flew over the beer deck in left field and the trees behind it.
The 21-year-old outfielder said he has felt "zero pain" in his knee and hopes to improve against left-handed pitching.
The veteran left-handed reliever said he chose the Nationals over four other teams because he felt comfortable with Washington.
Tanner Roark starts in place of resting Doug Fister.
Tanner Roark will make replacement start Friday against the Houston Astros in Viera.
He is the oldest regular position player on the team and has an ideal target of games played for 2014.
Also, Jordan Zimmermann fired three scoreless innings in his second start of the spring.
Jordan Zimmermann makes his second start of the spring.