Keeler: If Karl Dorrell, CU Buffs want to shock the world, Brendon Lewis can’t be learning on the job at QB. Not with TCU, Air Force, Minnesota and UCLA up first.

BOULDER — Karl Dorrell bounced to the interview tent Tuesday the way a little kid approaches a state fair midway for the first time, with a smile on his face and a spring in his step.

“Everybody starts with (the mode of) they’re kind of anxious and excited or happy and all that stuff,” the third-year CU Buffs football coach offered at his first preseason camp media scrum. “And then usually by practice 12, it ends up being a different tune, because they’re getting sore and beat up and tired and all that stuff. But these guys, I think, are showing a level of maturity that I haven’t seen since I’ve been here.”

Brendon Lewis used the word “fun” five times over one three-minute stretch. J.T. Shrout, the Tennessee transfer and Lewis’ top competitor for the CU’s No. 1 quarterback slot, snuck up behind the local scribes while Maddox Kopp, another import at signal-caller, was talking. Shrout then held out a fake tape recorder, nodding playfully with fake interest until he elicited a real giggle from his new teammate.

“You come in with a different attitude,” said Shrout, whose first season in black and gold was lost before it even began, thanks to an ACL tear suffered last August that put him on the shelf and put the Buffs offense in a pickle.

“Coach talks about the ‘dog days’ of camp … You get guys (saying), ‘Man, I gotta go do this today?’ It’s kind of an attitude (for me) of, ‘Man, I really get to go do this!’ You know, not taking anything for granted.”

They need him. Criminy, they need somebody.

Against teams that weren’t coached by Ed McCaffrey, the Buffs scored all of 20 points combined last September. If that happens this time around, they’ll be 0-4 right out of the gate. And you can kiss 2022 good-bye before Columbus Day.

Have you seen the dance card? The curtain lifts against TCU, at home, under the lights, on Sept. 2. Not to startle anyone, but the guys running the Horned Frogs’ offense now — new head coach Sonny Dykes and coordinator Garrett Riley — steered SMU to 38.4 points per game last fall, 10th in the country.

At Air Force in Week 2? 30.8 points per game in 2021, thanks to 328.4 yards per tilt on the ground. Zoomies coach Troy Calhoun had his crew running circles, literal and figurative, around Mel Tucker’s defense in Boulder three years ago.

At Minnesota the next week? 25.5 points on 198.1 rushing yards per game. And do we need to remind you what happened last September, the first true “measuring stick” game for the Buffs after UNC and Texas A&M? The Gophers got the stick out and whacked poor Ralphie about the head with it, a game that got so out of hand that poor old Folsom Field started falling apart at the end.

UCLA on Sept. 24? 36.7 points per game, 12th in the country and tops in the Pac-12.

The schedule won’t wait for the next CU quarterback to find his sea legs, new scheme be darned. If the Buffs want to shock the world, and every magazine from here to Nantucket that’s pegged them to land at or near the Pac-12 basement, they need to start fast.

“We’ve shown exceptional growth from Day 1 last year to Day 1 this year,” Lewis said. “You can just tell the guys, the way we’re moving the ball, the way the ball is getting spread around now, all the guys know their assignments.”

Some whispered at this time a year ago that the starting quarterback job was Shrout’s to lose — at least until his knee popped while trying to cut during an intrasquad scrimmage. The scrambling showed early, as Lewis played quarterback for the opening six weeks of 2021 how a deer plays in front of oncoming headlights.