UCF's turnaround from winless to a bowl team last season was in large part due to the consistent play of the defense, a unit headlined by a strong defensive line and senior-laden secondary and linebacker corps.

This spring, defensive coordinator Erik Chinander looks to retool a unit that graduates all four defensive back starters (cornerbacks Shaquill Griffin and D.J. Killings, safeties Drico Johnson and Tre Mutcherson) and three of four linebacker starters (Demeitre Brim, Mark Rucker, Errol Clarke). That's a lot of experience to replace as those players comprised seven of their top nine leading tacklers.

The good news is outside linebacker Shaquem Griffin, the reigning American Athletic Conference Defensive Player of the Year, returns for his senior season.

The defensive line should be a strength with the return of all key players. Senior nose guard Jamiyus Pittman, the most experienced of the bunch, is considered the team leader on the entire defensive side. Tony Guerad led the linemen with 3.5 sacks last season. Trysten Hill has a promising future, obliterating team strength records as a freshman.

UCF held their first full scrimmage on Monday.

"I think it was exactly what we expected with that first group," Chinander said. "We were rotating some guys in that first group. When the first group was in there, communication and effort was high. We were playing really well. When the next group got out there, whether it was a mix of ones and twos or twos and threes, that group struggled to get lined up and be effective out there. They did some nice things, that two group and three group, but communication is not all the way there yet. We've got to figure out who will be some leaders in the two group. You always want leaders with the ones, but you need leaders with the twos so when they're out there they can be be loud and be confident."

In the secondary, Chinander says they've been rotating players among different teams to see how they can play together with some receiving double reps.

"We're getting a good look at guys," he said. "I think some of those young guys are going to help us. The older guys are stepping up. It's going to be hard to replace those guys in the back end, but these guys are doing a nice job right now."

They may not have as many starts under their belt, but the current No. 1 safeties - Tre Neal and Kyle Gibson - have seen extensive action the past two seasons. They current lead the first unit.

"The normal suspects are starting to show," Chinander said. "It's funny, once those guys get to be the starter, once they wear the big hat, their true colors show a little bit. I think Tre Neal and Kyle Gibson have been doing a great job... They're not starters yet, but are being given a run with the ones. Their chests have puffed up a little bit. They have a little more swagger, a little more confidence in their calls. That's great to see."

Behind Neal and Gibson, three players have been seeing the bulk of the action on the second team.

"Right now, Brandon Scott and Shawn Burgess-Becker and Richie Grant are rolling with that second group of safeties and trying to push the ones," Chinander said. "We're trying to figure out if one of those three is the nickel, the dime. Or is it going to be one of those other corners? With Shawn and with Richie Grant and Brandon Scott, those guys are all playing well enough that they're going to play somewhere. It's just where? Will it be in the rotation at safety or nickel or dime? Where we will put them?"

The top cornerbacks include a couple players who have seen prior action (Nevelle Clarke and Rashard Causey) in addition to two younger players (redshirt freshman Brandon Moore and true freshman Antwan Collier).

"At corner, there's going to be some big-time competition," Chinander said. "Obviously you've got Nevelle Clark doing some nice things. Rashard Causey. The young guys, Brandon Moore and Antwan Collier. Collier has been on campus for a couple weeks, he probably should be at prom this week, but he's playing spring ball. Those guys have done a nice job. Then Bryon Brown is working back from that injury. He's looking good."

Brown suffered a torn ACL last preseason and is still limited in what he can do this spring, but is expected to be fully cleared by the summer.