"Things are not going my way," the 26-year-old said. "I make a bad pitch, they get a hit. I make a good pitch, they still get a hit.
"I have to keep fighting and try to get better in my next [start], because the first three have been terrible. I have to keep my head up and keep working."
Peralta said again what he said all spring, that he feels healthy and strong, ready to turn the page from a poor 2015 season ruined by a left oblique strain.
If the problem isn't physical, might it be mental?
No, Peralta said.
"The mental side, I'm fine, man," he said.
"I really think Wily's close," said manager Craig Counsell. "I know he's frustrated; we're frustrated. But I think there are some things to take out of today's game that we can go forward with. It's always going to boil down to being consistent. He's going to have to continue to work, but I think there are some positives that he can take into his next start."
"I think his changeup was a weapon today against some of the left-handed hitters," Counsell said. "I thought when he was down in the zone, there was good sink. I thought the last two innings, he threw the ball really well. It's close. We just have to keep moving forward and get consistent."
Adam McCalvy is a reporter for MLB.com. Follow him on Twitter @AdamMcCalvy, like him on Facebook and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.