At times in last week's season-opener, both lined up side by side against one of the toughest offensive lines in the nation. In the first game of his college career, Leaders recorded four solo stops and seven tackles overall coming off the bench for starting nose guard Tim Tebrink.
"He definitely had an impact," said Cyclone Coach Dan McCarney. "I'm real proud of him. He had the same look in his eye out there Saturday against Florida State on national television as he did when he was in our high school camp two summers ago. He's got the workman-like attitude, a great look of focus and loves playing the game. He never gets too high or too low. He's special. He's going to play a lot of football this year.
"I've never been around too many freshmen that could go out there and play as many snaps as he did in his first game and hold up in there. He was solid and did some real good things. He didn't make a whole lot of plays, but sometimes at that position it's not making plays as making darn sure that our defense operates and giving other people opportunities to make plays."
The effort even drew the praise of the grizzled veteran Carstens, who has already stood up to tough competition for more than two seasons.
"He's a tough kid," Carstens said. "He goes in there at 18 years old and plays against Florida State. He didn't flinch. It's a good feeling having another tough kid in there and somebody that can take on blocks and make plays. He's a great player and is going to have a great career here."
Carstens played the entire game, starting at defensive tackle and drew numerous double teams from all areas of FSU's offensive front. He finished with five solo tackles and three quarterback hurries. He also played various spots along the defensive line, including lining up at defensive end, as ISU inserted different packages to match up in pass coverage.
McCarney said the defensive plan is to get Carstens in the role he can be the most effective in.
"We want to get the best lineup out there on the field that we can," McCarney said. "Certain situations he may be somewhere we think we might be a little better against the run. Sometimes he may be lined up where we think that combination is better as a pass defense. He can line up and play any of those spots. He's one of those guys. We'll continue to roll him in there at each of those three positions."
ISU's scheme currently has Carstens playing at a three-, five- and seven-technique defensive lineman. A three-technique is an outside shade on a guard, while a five-technique has him lining up at an outside shade of the tackle.
When Carstens is positioned at defensive end, he is in a seven-technique which has him over the tight end. Regardless, Carstens says, he is still facing offenses set on taking him out of the equation.
"I'm seeing a lot of that stuff," Carstens said. "I actually see a lot less double teams when I'm in a three-technique at tackle. A lot of times I've got the offensive tackle coming down on me. I get that as an end, too, with the tight end. It's really a similar position, so it doesn't matter to me much."
The occasional switch to defensive end has been the biggest adjustment, he says.
"Coming into (the Florida State game), I worked on playing end about a practice and a half," he said. "So I wasn't really used to it. It's not just playing the position and knowing what you've got to do. After you've played it for a while, you get good and can pick up on different stuff. It's going to come to me with experience."