"I wish I could tell you. Anybody, including myself, I've never seen anything like that, I don't know what happened," Gregerson said. "I didn't feel bad, I don't feel like I was missing my pitches by enough to have something like that happen. I really don't know. It's never happened to me like that.
"It all happened really fast and I couldn't tell you how. That's pretty much it. I don't have an answer. I wish I could say I felt [bad] and I was throwing meatballs over the middle of the plate, but that wasn't the case."
Among the five hits Gregerson gave up were homers to Eric Hosmer and Salvador Perez that put the game out of reach for the Astros' third straight loss after opening with three straight wins.
Astros manager A.J. Hinch commented after the loss that at one point he noticed Gregerson, who also walked a batter, had thrown 14 pitches and allowed five runs.
Gregerson's 16-pitch outing is one he wants to put behind him.
"I just want to pitch," Gregerson said. "I know that what happened last night happened, but the only way to get through it is to go out there and throw a scoreless [inning] as soon as possible.
"I'm ready whenever. I don't feel like I'm injured, I'm not struggling. It was just a bad night."
Richard Dean is a contributor to MLB.com based in Texas. This story was not subject to the approval of Major League Baseball or its clubs.