The Nationals recalled Harris from Triple-A Rochester on Monday, Bobby Blanco of MASNSports.com reports.
Harris could be in line for a temporary stay with the big club, as he was called up as a replacement on the 26-man active roster for Trevor Williams (personal), who was placed on the bereavement list. Williams is expected to return from bereavement leave before his next turn in the rotation comes up this weekend in Cincinnati, so expect the Nationals to demote a reliever to Triple-A to make room for him at that time. Harris won a spot in Washington's Opening Day bullpen but was sent to Triple-A on May 20 after recording a 5.40 ERA and 1.80 WHIP across 18.1 innings.