Harper believed the excitement at practice spilled over from strength coach Joey Batson and his crew's work over the summer.
"They really put their heart and soul into us this summer," Harper said. "We've been really pumped up, amped up in the weight room, running and everything.
"It's the first day of practice. There's going to be a lot of intensity."
Practice for Tajh Boyd was easily more intense than what he remembered last December, which was his last official practice at the US Army All-American game. Even amongst the best high school players in the country, Boyd said practice on Tuesday was a lot more fast-paced.
The competition level stood out too.
"That was just for fun at the All-American game," he said. "We're out here competing for starting spots. But you can't win a starting spot on the first day."
Freshman QB Tajh Boyd said his knee is about 85-90 percent entering the start of preseason camp.
The most talked about knee in Clemson since Signing Day, which isn't quite 100 percent right now, sits somewhere at or between 85-90 percent. At times on Tuesday Boyd said he almost forgot about the injury.
"I feel a little pain, which they said is normal right now," he said. "It's kind of awkward, just because you don't think about it really.
"I'm just out here trying to push myself the best I can."
The guy who has set the pace for everyone else to be the best they can was excited to be back on the field. C.J. Spiller, life-size Heisman Trophy campaign poster and all, isn't allowing any room for error.
More importantly, there won't be a lack of effort on the practice field.
"I'm going 100 percent every time I'm in there," he said. "If my teammates see me doing that with everything surrounding our program, I think that will feed off on them. That's something I'll have to continue the whole camp, not just today."