Hernandez, 28, is 4-6 with a pair of saves (in seven opportunities) and a 5.59 ERA, allowing 30 ER in 48.1 IP, with 20 walks and 50 strikeouts over his 48 relief appearances for the D-backs. Hernandez was optioned to Reno on August 1. In 9 games for the Aces, he had two saves and a 0.93 ERA (1 ER in 9.2 IP), holding opponents scoreless in 8 of 9 contests. He had 12 strikeouts with 6 hits and 5 walks.
Sipp, 30, was 3-1 with a 3.94 ERA (14 ER in 32.0 IP) in 47 games with Arizona in 2013. He was acquired as part of a 3-team trade with Cincinnati and Cleveland on Dec. 10, 2012. Sipp was designated for assignment then optioned to Reno on August 4. In 9 games for the Aces, he had 1 win, 1 save and held opponents scoreless in 8 of 9 outings, allowing 1 unearned run in 10.0 innings. He had 12 strikeouts with 3 hits and 5 walks.
The D-backs active roster is at 27, so there may be additional roster moves made as the need arises. The Aces still have a couple of games to play, so we'll probably wait until their season is over.