Leone made only three appearances with the D-backs after being acquired from the Mariners last June in the deal that sent Mark Trumbo and Vidal Nuno to Seattle. The 24-year-old righty went 8-2 with a 2.17 ERA in 57 appearances as a rookie in 2014, but he racked up an 8.40 ERA over just 13 appearances between Seattle and Arizona last season.
Hernandez, meanwhile, spent last year with the D-backs after being selected from the Rays in the 2014 Rule 5 Draft. The 22-year-old backstop logged just 36 plate appearances in 18 games with the big league club.