Maybe it was the three straight days of 5 a.m. wake-up calls for sunrise practices.
Maybe it was worries about class work as summer school winds down.
An enraged Mark Stoops isn't interested in excuses.
"You know I'm not giving them any place to hide," the Kentucky football coach said Wednesday morning, the third day of camp. "Not good enough. Just not tough enough, not enough energy, weren't clean enough in our execution on either side of the ball. So, just wasn't good enough."
It was the Cats' first day in full pads.
Coaches expected that to rev up the players.
"They hadn't put pads on in a long time," defensive coordinator D.J. Eliot said. "I thought they'd be excited. I thought they'd be flying around. I thought we'd have to slow them down, not speed them up."
With Kentucky's season opener looming Aug. 30 at Commonwealth Stadium, the coaches have come to expect more from the players.
"I'm not calculated," Stoops said when asked about having a bad day so early in fall camp. Last season the head coach's first tirade about effort didn't come until two weeks in. "I don't pick out certain days on my calendar and come in here and rant and rave. I'm not going to do that. Just wasn't good enough."
The expectations are higher this season, several players said.
They expect more from themselves and one another.
"Today wasn't our character," senior defensive tackle Mike Douglas said. "We're a lot better team than this. I think everybody knows from top to bottom that we're better than this."
Defensive players available for interviews Wednesday morning said there was disappointment all around, but especially on their side of the ball.
"We have to be more physical as a defense," cornerback Nate Willis said. "We kind of came out soft. We weren't banging with our first padded practice. He wanted us to be way more physical, and I feel the same way. The defense feels the same way.
"The offense did pretty well. They kind of got off on us today because we weren't physical enough. So we have to come out tomorrow and be way more physical."
Stoops said he would address effort problems internally and with specific players. The entire UK defense was on the field doing extra cardio work after practice.
With more leadership in the locker room now, the players said Wednesday's problems were going to get corrected.
"If we nip it in the bud now, it'll set us for the rest of the year unless we let this day linger around, linger around and create a snowball effect, then we'll have a problem," Douglas said. "I expect us to nip it in the bud right now."
Stoops hopes the silver lining to a bad third day will be the emergence of leaders.
"We'll correct them in meetings," he said. "We'll get out here and have walk-throughs. We'll push them and we'll do what we need to do, but we absolutely need leadership in our program to take charge."