"You want a guy that's going to be able to step up, that's going to be able to give you the same elements from the standpoint of a three-down back that you're going to be able to use out in space, but most importantly, in pass protection," Wilks said. "That's the key, and those guys are getting that teaching."

If Johnson remains healthy, snaps could be few and far between for the other running backs. He will need breathers, so a backup should see the field occasionally, but Johnson is such a versatile player that he can be utilized in any situation.

Even so, the health risk is great at the position, and the Cardinals must always have a contingency plan. Johnson missed all but one game a season ago, and the team has cycled through myriad running backs the past few years due to injuries.

Edmonds is in the midst of an "All or Nothing" binge, which details how Johnson first rose to prominence as a rookie.

"David Johnson was three (on the depth chart), and then Andre Ellington got hurt," Edmonds said. "Chris Johnson got the start but David Johnson got his first career touchdown, and the next thing you know, he's the man. Pro Bowl. All Pro. Everything."

Johnson is a special talent, but General Manager Steve Keim made clear his desire to add depth by spending his fourth-round draft pick on Edmonds. Logan was drafted a season ago as well, giving the team some intriguing athletes behind their superstar.

"We've got a lot of new pieces, a lot of new faces, a lot of young energy," Logan said. "It's going to be fun. I feel like a lot of people don't expect what we're going to do. We're going to put on a show."

Logan expects the pecking order to become clear as training camp moves along and each player shows what he can do in pads. Wilks has fostered a sense of competition at every position group, but the backup running back spot seems to be among the toughest to gauge.

Each reserve pledges to keep his head down and battle, awaiting the official word from the coaches.