Herrera was put on the 10-day disabled list due to a right rotator cuff impingement prior to Wednesday's game, Chelsea Janes of The Washington Post reports.
Herrera will miss some time after exiting Tuesday's contest against the Braves with right shoulder tightness. The club deemed his injury as a rotator cuff impingement following an MRI, but declined to offer up a timetable for his eventual return. This opens up the ninth-inning spot for the time being. With Sean Doolittle (foot) also on the DL, look for Ryan Madson to receive an opportunity as the Nationals' closer. Koda Glover was recalled in a corresponding move.