Werth broke his left wrist in Sunday night's game with the Phillies when he tried to make a sliding catch in the sixth inning. A steel plate was inserted in his wrist, according to the MLB.com report, which cited a baseball source.
Werth injured the same wrist in 2005 as a member of the Dodgers and missed the entire 2006 season as a result. He hurt his wrist in the spring of that season and played 102 games before undergoing surgery to repair a torn ligament in the wrist.
The Nationals are hoping to return third baseman Ryan Zimmerman from the disabled list this week, and first baseman Adam LaRoche is expected to return to the lineup as well. The loss of Werth further solidifies Bryce Harper's spot on the big-league roster.
Werth was hitting .276/.372/.439 with three home runs in the team's first 27 games.