DEFENSIVE LINE
The offense wasn't the only unit that went through a scheme change during the spring. On defense, Notre Dame switched back to the 3-4, which it played in 2007 and 2008, after going with the 4-3 last year. Defensive players seem to agree that the Kelly's 3-4, which produced high sack (10th in the FBS in 2009) and tackles for loss (2nd in the FBS in 2009) totals at Cincinnati, fits the Fighting Irish's personnel better than the 4-3.
"In the 4-3, the defense is just always going, going, going," senior Emeka Nwanko said. "In the 3-4, you get to sit back and read the keys."
In terms of positions, the only player who made a move was junior Ethan Johnson (6-4, 280), who switched from defensive tackle, where he started 11 games last year, to defensive end, where he was recruited to play and played as a freshman. Johnson was productive last year, posting 32 tackles, including four sacks.
Starting opposite Johnson will be junior Kapron Lewis-Moore (6-4, 275), who started nine games last year. Lewis-Moore, who's added 50 pounds since arriving as a freshman, was the Fighting Irish's sixth-leading tackler last year, registering 46, including seven tackles for loss.
The player who did the most for himself in the spring was Nwanko (6-4, 280). Nwanko didn't play last year and wasn't expected to contribute much this season. But he impressed the coaching staff during the spring enough to promote him to the second team, and he led his team in the spring game with five tackles and a sack.
"I just feel like the light is coming on," Nwanko said. "I am adjusting well to the new system."
Manning the middle of the 3-4 will be senior Ian Williams (6-2, 301), one of two players on the roster to have played in every game during his career. Williams finished last year with 39 tackles, including six tackles for loss.
Williams will have to work on his stamina, because Notre Dame is thin on experience behind him. Junior Brandon Newman (6-0, 297) played in one game last year, and sophomore Tyler Stockton (6-0, 290) didn't play in any.
LINEBACKERS
Notre Dame's linebacker corps already has one standout in sophomore inside linebacker Manti Te'o. Thanks to Kelly's 3-4 defense, it could have another in junior outside linebacker Darius Fleming (6-2, 245).
Among other things, Kelly's 3-4 turns teams into sack stars. Last year, Cincinnati finished 10th in the FBS in sacks with 2.85 per game. The primary beneficiary of the aggressive system is the pass-rushing linebacker, which Fleming will become. He's already shown a penchant for finding the backfield. Of his 29 tackles last year, 12 were for loss.
Backing up Fleming and Smith will be senior Kerry Neal (6-2, 244) and junior Steve Filer (6-3, 235). Neal has plenty of experience, having played in every game since arriving as a freshman, including 21 starts. Filer appeared to be running out of chances to live up to his potential, but he flourished during the spring, leading his team with 12 tackles during the spring game.
Playing opposite Fleming will be senior Brian Smith (6-3, 234). Smith's ball-hawking skills are apparent by his stats -- he finished with 71 tackles last year, including 5.5 tackles for loss, and a pair of interceptions. Although Smith is a capable pass rusher, Kelly believes his skills will be better utilized against the pass. He'll be given the freedom to move around to better cover running backs, tight ends and receivers.
Te'o will start at one inside linebacker position, after starting 10 games as a freshman and finishing with 63 tackles, including 5.5 tackles for loss. Te'o called the defensive signals during the spring and probably won't see the sideline too much during the fall.
"He's a Mike linebacker who you can keep on the field," Kelly said. "He's not a guy you take out on third down."
The other starting linebacker position is down to a pair of players -- junior Anthony McDonald (6-2, 230) and junior David Posluszny (6-0, 225). McDonald made only 10 tackles last year, but he impressed coaches during the spring with his physical play and played with the first team in the spring game.
Posluszny has less experience, playing in only 10 games last year. But he had a good spring and remains high on the depth chart.
DEFENSIVE BACKS
Throughout his career at Notre Dame, senior Harrison Smith (6-2, 212) has enjoyed the luxury of being able to play safety and linebacker. Last year he started the first six games at safety, but after struggling moved to linebacker, where he started the final six.
Smith won't enjoy that luxury in Kelly's defensive system. Kelly envisions Smith as strictly a safety. Harrison performed well in the spring and appears to have locked up a starting job once again.
Smith's major strength is his tackling ability. He made 69 tackles last year, third on the team.
Starting opposite Smith is another position nomad, junior Jamoris Slaughter (6-0, 195). Slaughter has played safety and cornerback during his career, but he appears to have found a home at safety.
"I thought we ran downhill from a safety position," Kelly said of the position after the spring game. "They were all around the ball today, Harrison and Jamoris Slaughter." The Fighting Irish have depth at the position in junior Dan McCarthy (6-2, 205) and sophomore Zeke Motta (6-2, 210). Motta played in all 12 games last year, mostly on special teams, while McCarthy saw action in five.
Aside from quarterback, no position will be scrutinized more than cornerback. Notre Dame's pass defense struggled last year, ranking 76th out of 120 teams in the FBS. The cornerback's received much of the blame. The good news (or bad depending how you look at it) is that all the major players are back from last year's team -- seniors Darrin Walls (6-0, 185) and Gary Gray (5-11, 190) and junior Robert Blanton (6-1, 190).
Walls isn't a playmaker, but he's consistent, having started 21 of his 32 career games. The best competition should occur on the other side of the field, where Gray will attempt to hold off Blanton. Blanton started eight games last year, making 38 tackles and picking off two passes. Gray started seven, finishing with 28 tackles and one interception.
Both players are attempting to live up to expectations. Blanton had a standout freshman year but wasn't quite as sharp last year, while Gray entered the program as the top cornerback recruit in the country, but he hasn't displayed top cornerback talent.