Butler said he went through his typical warm-up and pregame routine and "felt pretty good about it." He then proceeded to kick nine punts for a career-low average of 34.8 yards per punt.
"That shocked me probably more than anything because he had been kicking so well," Cardinals coach Bruce Arians said. "To come into this game and punt so poorly in the first half and it never swapped field position for us.
"It was going to be huge for us all game and he really didn't perform up to his ability."
Of his nine punts, the Carolina Panthers returned eight of them. One was muffed by Carolina's Brenton Bersin and recovered by Arizona's Justin Bethel. From those eight, the Panthers' starting field position was about the 44-yard-line.
Carolina scored 17 of its 27 points off Butler's punts.
"Just a bad day to have a bad day," Butler said. "Didn't help the defense out. My job is to help win field position and I contributed to us not winning field position."
Butler said he figured out what the issues were: His drops were inside. He was trying to correct the mistakes on the field but couldn't adjust it until late in the game. The weather, chilly and rainy, didn't impact his punting, Butler said.
"It cost us for sure," he said.
Butler's punts went 20, 28, 33, 52, 31, 31, 37, 43 and 38 yards. He landed one inside the 20-yard-line after finishing the season with the highest percentage of punts inside the 20. In the second quarter, Arizona forced Carolina to punt after the Panthers started at their 17 because of a Butler punt. After his next punt, the Cardinals picked off Cam Newton.
The Cardinals' defense locked down the Panthers in the fourth quarter after Butler punted, forcing a punt, recovering a fumble and stopped them on downs. But Butler's early-game struggles proved to be too difficult for the Cardinals to overcome.
"I put the defense in a really bad spot multiple times," Butler said. "They did an extremely good job trying to get out of those spots but didn't do a good job winning field position.
"It puts the blame on my shoulders, no doubt."