Both were in the starting lineup for Tuesday night's game against the Miami Marlins, with Werth batting third and playing left field and Zimmerman hitting fifth. Werth came into the game batting .208, Zimmerman batting .209.
To make room on the roster, the Nationals optioned outfielder Matt den Dekker and sent infielder Emmanuel Burriss outright to Triple-A Syracuse.
Werth missed 61 games with a broken left wrist. Zimmerman missed 49 games with plantar fasciitis in his left foot.
Werth last played on May 15. Zimmerman's last appearance was June 9.