Hernandez was promoted to the big leagues prior to Friday's game against the Pirates.
Hernandez will provide some more depth out of the bullpen for the Reds, as he's already made 10 relief appearances with the club this season. During 15.1 innings, he's posted a 5.28 ERA and 1.17 WHIP, which includes a disastrous outing against the Diamondbacks in late July. Besides that game, he's accumulated a solid 1.88 ERA and 18:8 K:BB for the year.