Hernandez will have the surgery performed by Andrews on Tuesday and will be lost for the entire 2014 season.
"It's disappointing, but we have to regroup," D-backs manager Kirk Gibson said when Hernandez was first diagnosed. "I don't have an answer for who will be there, but we do have some guys with experience in the back end. Our bullpen will have a different dynamic, but it's just another opportunity for someone else. We still have a lot of good choices."