Johnson returned to practice Saturday (a non-padded affair) and coach Mike Pettine said the upcoming fortnight is crucial for the young back.
"It's important," Pettine said Saturday, per Scout.com. "He looked really good for us in shorts in the spring but he needs live reps. That's asking a lot of a rookie to put him out there Week 1 with minimal full contact reps. These next two weeks are big for Duke."
Pettine added that he's not worried about Johnson from a "mental standpoint," due to similarities in the offense the back ran in college.
"He's far ahead of most rookie backs that I've been around," Pettine said.
The third-round pick said he thinks he'll be ready to see preseason action for the first time next week against the Tampa Bay Buccaneers.
Johnson added that he doesn't believe the missed time has hurt him because of his mental preparation.
"I don't," he said. "I think every day I wake up it's football. Whether it's raining, I think it really doesn't matter, it's football. I come out here, I compete, I play football something I've been doing since I was a kid.
"Missing time (doesn't) really set you back unless you don't take the right steps while you're out. If you're lollygagging, not paying attention during the meetings, doing things like that then it sets you back."
The door is open for Johnson, but he needs to get -- and stay -- on the field first.