Jayson Werth has a "barky" right knee, so Matt Williams wanted to give him two days off.
Mired in a slump, Adam LaRoche appears ticketed for a day off Wednesday.
Bryce Harper returns to the lineup and Jordan Zimmermann makes his first start since his bicep strain.
Bryce Harper wants to play, but says he's "totally fine" with Matt Williams sitting him against a left-handed starter.
Doug Fister faces Franklin Morales as the Nats start a three-game series in Colorado.
Everything is the same, except Jose Lobaton is starting and Wilson Ramos has the day off.
The Nationals use their rubber stamp lineup against right-handed Matt Garza.
The Nationals open the second half of the season with their standard lineup.
As lineups were announced, Mike Matheny explained why he chose Tyler Clippard to represent the Nats.
Bryce Harper is back in the lineup and starting in left field, and Jose Lobaton gives Wilson Ramos a day off.