Indiana's defense relies on Replogle Bros.

If Indiana's defense finally turns the corner this season, the Replogle family figures to play a key role.

Hoosiers senior Tyler Replogle is the defense's undisputed leader, not to mention the only returning starter at linebacker. His younger brother Adam was IU's only true freshman to see the field last season and will be a factor on a new-look defensive line.

More help is on the way, as linebacker Mike Replogle already has given Indiana a verbal commitment for 2011. And there's an even younger Replogle who plays defense, Jake, a freshman linebacker at Centerville (Ohio) High School.

"I'm sure he'd love to come here, too," Tyler Replogle said of Jake. "It worked out really well, pretty much a dream come true, growing up, playing together in high school, and then getting another chance to play together in college. It's just been a real dream."

Tyler started nine games at strong-side linebacker last fall and finished second on the team with 80 tackles (61 solo), including 6.5 tackles for loss, two sacks and an interception. As Matt Mayberry and Will Patterson depart, he steps into the featured role at linebacker this fall.

"There's no question he's the leader of our defense," head coach Bill Lynch said. "He's everything you're looking for in a Big Ten football player. He's tough, he's aggressive, he's a great leader, a great student, has a passion for the game. He's played a lot of football for us, so the guys kind of rally around him."

Co-defensive coordinator Joe Palcic calls Replogle "one of the toughest kids we've ever been around."

"He's not flashy," Palcic said. "You look at him on the field, he looks sort of average, but he has great smarts and great toughness."

Indiana has transitioned to a 3-4 defensive alignment this spring, a change Tyler Replogle welcomes. He said the alignment helps the line better disguise blitzes and frees up himself and the other linebackers to make more plays.

Although Replogle still plays on the strong side, he lines up inside when the defense goes to the 3-4.

"It gives us a lot more flexibility," he said. "We're blitzing a lot more, obviously, since we're sometimes sending one, maybe two linebackers. It allows us to get pressure on the quarterback, drop back in coverage, and frees up the other linebackers [to stop] the run."

Adam Replogle started the final 11 games last fall at defensive tackle and recorded four sacks and five tackles for loss. He also showed his versatility by playing fullback in Indiana's final three games.

Replogle has continued to make progress this spring and recorded two sacks and three tackles for loss in Saturday's scrimmage. Despite his size (6-3, 290) and experience at tackle, Replogle moved to defensive end this week and could fill in there as IU loses two multiyear starters (Jammie Kirlew and Greg Middleton).

Palcic said Adam is the superior athlete between the brothers, but both will play big roles if Indiana plans to end its defensive struggles, which have lasted for more than a decade.

"We're very fortunate to have both of them," Lynch said.