Also, the Nationals are among the teams that have inquired about free agent infielder Asdrubal Cabrera.
The shortstop played second base for the Nationals and would be open to staying because he wants to win a World Series.
The infielder said he could play Tuesday if he feels good after his normal pre-game routine on Monday.
Asdrubal Cabrera exited Sunday's Nationals win with tightness in his right side, but it shouldn't be a major injury.
The second baseman has formed a strong double play duo with Ian Desmond and provided some key hits.
Cabrera is "fine" after getting clocked Monday night, and LaRoche finally has a walk-off homer to his name.
Nate McLouth headed for more tests on pesky shoulder, Asdrubal Cabrera gets a rare start against a lefty, and Matt Thornton is pitching himself into Matt Williams's confidence.
Jayson Werth is back and starting.
Doug Fister's ERA is down to 2.20, which would be the fifth best in baseball if he qualified.
Switch-hitting infielder Asdrubal Cabrera has played little against left-handed pitching, and he has had to adjust to that.