Herrin was recalled from Triple-A Columbus on Saturday, Zack Meisel of The Athletic reports.
Herrin has made nine appearances at the big-league level this season, striking out 13 battings in 9.2 innings but struggling to a 7.45 ERA. He owns a 3.63 ERA in 17.1 innings at the Triple-A level. James Karinchak was optioned in a corresponding move.