Topa, who turns 32 on March 7, went 0-0 with a 4.91 ERA in seven appearances for the Brewers last season. Topa also went 2-0 with a 4.34 ERA in 17 appearances with Triple-A Nashville.
He was out until August while recovering from a right forearm flexor strain.
Topa has a career record of 0-1 with an 8.35 RA in 17 appearances.
Hernandez, 22, was 9-5 with a 3.39 ERA while striking out 143 and walking 54 in 116 2/3 innings for Single-A Modesto last season.
→ Continue reading at King5