PITTSBURGH -- It’s been a while since Zac Gallen had a game like this.

Yes, the D-backs right-hander called one of his starts earlier this year a “clunker,” but it was only one if you go by his exacting standards -- he allowed three runs in that game. He called another couple of starts “grinders,” but again, they were good outings that most pitchers would gladly take.

Gallen’s start Friday night at PNC Park, though, was an actual clunker and a grind for him as he allowed eight runs (five earned) over just 3 2/3 innings as the D-backs fell, 13-3, to the Pirates.

“It was a very different Zac outing today,” D-backs manager Torey Lovullo said. “I was scratching my head for the two innings after we took him out of the game trying to figure out what happened.”

When he was warming up in the bullpen, Gallen didn’t feel like he had great command.

“I felt OK,” he said. “Just kind of … the ball wasn't really going where I wanted it to. I wasn't trying to put too much stock into it really, you can’t get too crazy with what goes on down there in the bullpen, but I just knew I wasn't super sharp. But sometimes when you're not sharp in the bullpen, you come out and you're sharp out there.”

That would not be the case Friday, even though he looked just fine when retiring the Pirates on just five pitches in the first.

Back-to-back doubles to lead off the second by the Pirates gave them a 1-0 lead, but in the D-backs dugout there was the expectation that Gallen would quickly settle back in.

“They were definitely aggressive,” Gallen said. “It's kind of a double-edged sword with teams being aggressive. If you’ve got really good command that night, it can work out in your favor, you can be pretty efficient, but I just didn't feel like I had great command. A lot of balls in the middle of the plate, just kind of had to grind. So it kind of worked out in their favor -- they were aggressive and I didn’t have good command.”

Things fell apart for Gallen and the D-backs in the fourth, when the Pirates sent 11 men to the plate in a seven-run inning that chased Gallen from the game.

The seven runs (four earned) were the most Gallen had ever allowed in a single inning, and the eight runs were the most he had ever allowed in a start in his career.

After he came out of the game, Gallen looked at some video of the outing on the iPads provided in the dugout, but he will go through his whole outing pitch-by-pitch at least once.

“I'll see, you know, what the deal is,” Gallen said. “I’ll do my normal throwing program throughout the week, trying to figure out why things were off. I mean, you don't want to have ones like these, but at the same time there's a human element to it and you're not going to be crazy dominant every time out. So it's just a learning experience, really.”

Gallen’s next outing will come against the Phillies and if history is any indication, he will produce a much better result.

“It was probably not establishing his fastball the way he has and just bigger misses than we've seen from Zac since the start of the season,” said Lovullo. “So it proves that he's human, he has bad days as well. I know that he's got four days in between to make this get better and I know he will work hard to make that happen.”