The Nationals announced the roster moves Monday before their series opener in Los Angeles against the Dodgers.
Werth sat out Sunday’s series finale in Oakland after he fouled a ball off his toe on Saturday. X-rays were negative, but he was on crutches and wearing a walking boot Sunday.
Werth fouled a ball off the same toe in spring training.
“Right now, it’s not looking good,” Nationals manager Dusty Baker said Sunday.
Werth is batting .262 with eight home runs and 18 RBIs in 47 games this season. Raburn, who was acquired by Washington last month in a minor-league trade with the Chicago White Sox, is a career .253 hitter in parts of 11 seasons with Detroit, Colorado and Cincinnati.
The Nationals also designated reliever Rafael Martin for assignment on Monday.
Information from The Associated Press was used in this report.