Over the past four games, dating back to Sunday's road trip finale in Oakland, the 'pen has allowed 14 runs in 10 2/3 innings. On Wednesday, it gave up three runs in four innings, and that doesn't include the pair of inherited runners that were allowed to cross the plate.
With closer Chad Qualls and setup men Tony Pena and Juan Gutierrez having thrown a lot over the past week, Hinch said Qualls and Gutierrez were unavailable Wednesday and he wanted to do all he could to avoid using Pena.
That left Leo Rosales and Esmerling Vasquez to pitch key innings late in the game.
"Guys are pitching in roles they're not necessarily accustomed to, but that they're going to have to pitch in at times in order to be successful," Hinch said. "A learning experience for a lot of those guys down in the bullpen that probably aren't used to pitching in those roles."
The D-backs were in a hole early thanks to a two-run homer by Adrian Gonzalez in the first off Billy Buckner.
"It's a mistake out over the middle of the plate, and Gonzalez doesn't miss many of those," Hinch said.
Buckner, who pitched very well in his last start in Oakland, did not have the same success this time around, allowing five runs on seven hits in five innings.
"He picked at the strike zone a little bit more than he did in Oakland," Hinch said.
Still, it wasn't a terrible outing for the right-hander, who left with one run in and two on in the sixth and Arizona training, 3-0.
Reliever Clay Zavada allowed both of the inherited runners to score, though, as the Padres built a 5-0 lead.
That usually would be more than enough for San Diego ace Jake Peavy, but Arizona managed to rally against him in the sixth.
The key hit was a two-run triple by Justin Upton, who has been red hot for the better part of a month. Upton scored on a single by Stephen Drew as the D-backs cut the lead to 5-3.
"Justin was locked in and battled," Hinch said. "He really put us in position to stay in it. Those are the types of at-bats we've talked about over the last couple of weeks where the game is slowing down for him and it doesn't matter what the level of competition is -- elite pitcher or average Major League pitcher or anyone that's out there. He takes full control of his at-bats, and that's good to see."
The D-backs chased Peavy in the seventh after back-to-back one-out singles, and they managed to push across a run to cut the lead to one.
Again, though, the bullpen was unable to keep the Padres at bay.
In a particularly ugly eighth inning, San Diego managed to tack on three runs thanks to a pair of errors and four walks, two of which came with the bases loaded.
"It just kind of compiled on us a little bit," Hinch said. "Certainly the free ones, the walks, are the toughest ones."
In the three-game series, the Padres managed to outscore the D-backs, 12-0, during the eighth inning.
"The eighth inning wasn't very kind to us in this series," Hinch said. "To give them credit, when they scored, they scored multiple runs. We just had a hard time getting through later in games."