Daniels’ preparation wowed USC coaches even in high school

The image is out there now for USC fans to hold onto: JT Daniels wearing the cardinal No. 18 jersey, a giant tattoo of the Trojan logo and the Coliseum on his right calf, throwing for more yards in his debut than has any other USC quarterback. There is no more build-up, only the hope for more of whatever moxie he brought to that fourth quarter against Nevada Las Vegas.

But to comprehend how an 18-year-old showed such poise in his first college game leading a storied program, you have to take a step back in time to the turn of the new year, where there’s another image stored in USC offensive coordinator Tee Martin’s memory:

Daniels, still a high-school junior, lugging his backpack full of books for his 11 classes into the McKay Center to watch film of the Trojans’ offense.

“After he had signed,” Martin said, “he was up here in the film room, made it to every spring practice. There were times when he had his homework up here in the staff room. He’d take a break and watch the tape. He would go out and throw to the wide receivers on his own. He attacked it as if he wanted to be the starter and was starting to prepare like a starter even before he enrolled in school.”

Martin isn’t the only staff member who carries around that image.

“I’ve never seen a high-school quarterback work as hard while he’s not even here as he did,” quarterbacks coach Bryan Ellis said. “That’s why he’s our quarterback.”

With each week that has passed since Daniels won the quarterback battle, his coaches have become a little more willing to share what makes him special. The more he plays and backs up their faith in him, the more that will come out. Clay Helton was not willing to say Daniels’ effort to be around the program during the spring made a big difference in him winning the job, which was actually another compliment.

“To be honest with you,” Helton said, “he’s just one of those kids, you hand him a playbook and he’s going to know it in a week, inside and out.”

Daniels, for his part, is a true believer in preparation. He believes in his physical gifts, too, but he would never lean on them. He spent so much of his rare free time during his intense last semester at Santa Ana Mater Dei driving back and forth between Los Angeles and his home in Irvine because he doesn’t leave anything to chance.

“I think that played a massive role in helping me to compete now,” Daniels said. “Had I not been able to come up during the spring, I think I would have been much further behind in terms of being able to execute the offense.”

The football study was the fun part, the carrot to get him through the grind of two course loads stuffed into one semester.

“I had to get it done to come to USC, so it was worth it,” he said.

Daniels knew deep down he was a college quarterback. Against the Rebels, he finished 22 of 35 for 282 yards and a touchdown. Helton said Daniels forced just one throw all day, which would have been an interception had the defender not dropped it.

It was not perfect, especially his timing with starting outside receivers Tyler Vaughns and Michael Pittman Jr. Watching film and knowing the playbook can only get a quarterback so far. With Daniels evenly splitting reps with Matt Fink and Jack Sears until the week of the UNLV game, and Pittman missing significant time in camp due to injury, it makes sense they started slowly.

“I’ve been playing with Amon-ra [St. Brown] since I was in the seventh grade,” Daniels said, “so there’s obviously going to be more timing and chemistry between us right off the bat. But Michael Pittman and Tyler Vaughns are two NFL high-pick receivers, elite talent. Nobody was mad at each other. We were like this close from three touchdowns to each other.”

Pittman dropped a would-be touchdown in the second quarter that would have alleviated a lot of nerves in the Coliseum Saturday.

“We went five for five on deep balls in one-on-ones,” Pittman said after Tuesday’s practice, “so I feel like we’re kind of getting there and making more of an emphasis to get a good relationship. We’re working on fixing it.”

This week, as Daniels faces his first road game at No. 10 Stanford, he will go back to what he does best, what put him in this position.

He was asked about his expectation for Saturday.

“I don’t plan on coming up with an expectation,” he said. “However it plays out, it plays out, and I’m sure I will adjust on the fly if I have to. I’m really just focused right now on getting to know their defense and understanding what they’re bringing.”

Etc.

USC starting center Toa Lobendahn, who missed the opener with a pectoral strain, practiced Tuesday in full pads. “We’ll see how he feels tomorrow,” Helton said. … True freshmen Palaie Gaoteote IV (meniscus tear) and Markese Stepp (concussion) returned to practice. … Tight end Josh Falo (tight hamstring) is “getting close,” Helton said.

brady.mccollough@latimes.com

Twitter: @BradyMcCollough