Yeah, I mean Putz has pretty much been the closer in AZ since Hernandez has been here. Also, Hernandez did have more blown saves (6) than saves (4) when he had the opportunity in 2012. He has pretty much been the 8th inning guy though. He was an outstanding 8th inning setup man last season. Stats are posted below...98 K's in 68.1 innings, 25 Holds, and a WAR of 1.7 which is pretty sick for an 8th inning guy.
This year, with the addition of fat fukk Heath Bell, they would sort of alternate throwing Bell and Hernandez in for the 8th with Zeigler taking the 7th if needed. With Putz hurt, Bell took the closer roll and Hernandez is back as the 8th inning man.