For starters, DeAnndre McDaniel and Rashard Hall, who combined for 14 interceptions in 2009, were joined by safety/cornerback/nickel back Marcus Gilchrist. As you would expect, Harbison is more than pleased to have those three back, but still sees room for improvement.
"In the back end, we're always going to have to work on technique and eyes and things of that sort because we get into different positions," he said. "One thing that impressed me (this spring) is we really worked a lot of technique work on our bump technique. I think we got some things in order there."
Coming out of the spring, Jonathan Meeks and Carlton Lewis are the backups at safety.
"Meeks had a good spring. So did Lewis," Harbison said. "Meeks is ahead of Lewis. Meeks is behind McDaniel. As far as Lewis, I think he's got some work to do, but he's a guy that should be right there."
The biggest task for Harbison is to find some sort of semblance in the order at cornerback with Butler and Chancellor both gone.
Gilchrist continued to move around and looks to be a starter at one corner with Byron Maxwell at the other.
"I just feel like the group grew because of their second year in the system," he said. "They understand why we call, what we call and understand the system better." (Roy Philpott)
Xavier Brewer and Coty Sensabaugh look to be the backups.
"Brewer did some things. He matured a lot," Harbison said. "Not to take anything away from Sensabaugh, but Brewer really stepped up his game in the spring and I was really impressed with him.
"Sensabaugh's technique got better on the outside and Brewer got strong on the inside. I need that and focused on that."
Spencer Adams was shifted from safety to corner mid-way through spring practice.
"That worked well. He's going to get better with reps," Harbison said.
Three more corners and two more safeties from the 2010 signing class are expected to be in for fall camp, looking to crack the two-deep depth chart. Bashaud Breeland and Desmond Brown will play safety and Darius Robinson, Garry Peters and Martin Jenkins are corners. Breeland could also end up in a similar role to Gilchrist one day.
Harbison expects every one of his freshmen to determine whether they'll see the field or not this fall.
"They're in control of that," he said. "If they can handle it, I'll play them. If they can't handle it, it's not best for me to play them.
"Meaning, if they can handle the system, if they can handle the pressure, they'll play. Some kids mature faster than others. I'll learn that with them being on campus and going through two-a-days and fall camp."
Based on what Harbison saw during spring practice, the defensive backs already on the roster can handle it.
"I just feel like the group grew because of their second year in the system," he said. "They understand why we call, what we call and understand the system better."