Besides that, the offense is going to look much different as Riley and coordinator Danny Langsdorf begin installing a pro-style system.
Armstrong, who'll be a junior this fall, got that message in his initial meeting with Langsdorf.
"First thing he told me was that I'm not going to be a running back." - Armstrong
Designed quarterback runs, zone-read keepers and times he fled when protection broke down accounted for most of Armstrong's 145 rushing attempts out of last year's multiple offense. In Riley's offense at Oregon State, Sean Mannion had 48 rushing attempts last year, with all but a few of those the result of sacks.
Riley said Armstrong's skill set lends itself to having some quarterback run game at his disposal, and the coach is excited about the possibilities. But it won't be nearly as prevalent as it was in the past at Nebraska.
"He wants me to sit in the pocket, deliver the ball when I can and make smart decisions," Armstrong said of Langsdorf. "That's what we've been working on."
Riley said he would divide the team into two groups for spring practices so he and his assistants can familiarize themselves with and better evaluate the players. The coaches will conduct two separate practices each day, with about 60 players on Team Red and 60 on Team White. There will be a special-teams session for all players in between the two main practices.
"I just think it's best for the players to have an opportunity to get coached and get some repetitions," Riley said. "I didn't want to have a team period where 22 guys were competing and 100 guys were watching."
The Huskers will practice 15 times, with the final one being the annual Red-White Game on April 11.
The offense was given the playbook about 10 days ago. Armstrong said it's his understanding he'll take half the snaps from under center and half out of shotgun. Another change, Armstrong said, is that the offense will huddle after most plays.
Armstrong, who played in a pro-style offense his sophomore and junior years of high school, said polishing his footwork would be an emphasis.
"That was the key to all my things I made mistakes on," he said. "My upper body and my lower body weren't in the right rhythm. One time my footwork may be really fast, but my upper body is slow. So that's kind of when the accuracy level of my balls went down."
Armstrong completed 53 percent of his passes for 2,695 yards and 22 touchdowns, with 12 interceptions. He said his goal is to hit 60-65 percent in Riley's system.
Riley said starters at other positions also will be listed No. 1 on the depth chart this spring.
"Guys who have played in games have an advantage because there's nothing like playing in the games," Riley said. "That is multiplied for quarterbacks. Our job is to give guys who haven't played much in games ample opportunity to compete, and then we'll have to make a judgment where that goes."