After almost flawless work at Class AAA Reno,
were returned to the
' roster Sunday, reinforcing a bullpen that has been taxed for much of the season.
Hernandez had two saves and allowed only one run in 9 2/3 innings at Reno, and Sipp gave up only one unearned run had a win and a save in 10 appearances. Both struck out 12. The two were expected to arrive in time for the D-backs' game Sunday after playing in Salt Lake City on Saturday.
"Our bullpen has bee overworked, and having additional arms will help us kind of spread it around a little bit and keep guys fresher," manager Kirk Gibson said. "I feel right now they are freshened up to an extent. I just don't want to get to a point where the guys are throwing four out of six days, four out of five days. We've had a fair amount of that in the last month."
The D-backs (69-65) have one off day in September as they make a run at the postseason.
Hernandez is 4-6 with two saves and a 5.59 ERA with the D-backs this year. He has five failed save conversions and has given up 10 homers in 48 1/3 innings, and the D-backs sent him down so he could get past that, Gibson said.
"David just got to the point where he really was in a bad spot," Gibson said. "We tried to take some pressure off him. We wanted to get him to relax and throw all his pitches. Hopefully that's happened."
Sipp is 3-1 with a 3.94 ERA in 47 games for the Diamondbacks. He has 18 walks in 32 2-3 innings.
"For Tony, throw more strikes. Walking guys and being behind in the count … it's not a good spot to be. Just more consistent with your pitch sequences and being able to execute a game plan," Gibson said.
The D-backs are expected to add a few more players, including a third catcher, after the minor league season ends Monday.