ENGLEWOOD, Colo. -- The cerebral challenges for offensive linemen are unique. That the Broncos' intricate offense emphasizes pre-snap checks and calls only increases the burden.

Cramming later this summer won't do any good to prepare the Broncos' two drafted offensive linemen for training camp. The intense study began this week, when they were handed their playbacks and iPads and channeled the focus typically used for undergraduate courses into football.

"One thing that benefits us now is that we don't have school," said sixth-round pick Matt Paradis. "I can spend a lot more time in the playbook and focus on that."

And this week, "a lot more time" has meant "almost every spare moment."

"You've got to pretty much be in your playbook every single chance you have, especially when you're a rookie right now, just starting off, you want to make sure you're crisp going into practice -- as crisp as you can be," said third-round selection Michael Schofield.

Added Paradis: "Every night when I go home to the hotel I got the playbook open. And that's just what I'm doing … I'm thumbing through it until I go to sleep."

The pace is faster, too -- even for non-contact work like this weekend's.

"You can tell for practice, especially individual, we're going non-stop, and when you're going non-stop at this altitude, it's no joke; it gets to you," said Schifield. "You start getting winded pretty quick.

But in general, the complex playbook the single biggest difference between college and the NFL. The Boise State offense in which Paradis flourished was closer to a pro style than the one in which Schofield started at Michigan, where his task was usually simple: line up and block the man in front of you.

"I mean, it's just totally different than what it was at Michigan," he said. "Michigan, it was pretty much zone left, zone right, you know exactly what you're doing.

"Here, pass [protection] is my biggest thing, because at Michigan it was pretty simple, and here, it's like, you've got to figure out what the [middle linebacker] is, and you've got to figure out if you've got the [weakside linebacker] or the [strongside linebacker]."

For that, Schofield knows he needs help. That's where the experienced hands on the field this weekend have their biggest impact.

The term "rookie minicamp" is a bit of a misnomer. There are plenty of practice-squad players around who did not take a regular-season snap last year. That group includes tackles Paul Cornick and Vinston Painter and guard Ben Garland.

"This would be a lot harder if it was all rookies right now, especially on the offensive line," said Schofield. "Those three vets, I mean, if I go out there and I make a wrong call, Painter's next to me, he's correcting me and telling me what I should be doing. So it's huge. It's a lot of help."

But help will only go so far. Schofield and Paradis know that progress will be predicated on what each does alone, when left with a playbook, a notepad, and time to study.