The Nationals placed Williams (personal) on the bereavement list Monday, Bobby Blanco of MASNSports.com reports.
Washington recalled reliever Hobie Harris from Triple-A Rochester to replace Williams on the 26-man active roster. Per MLB rules, players must spend at least three days on the bereavement list but no more than seven, so Williams could be activated by the time his next turn in the rotation comes up this weekend in Cincinnati.