UNIVERSITY PARK -- The Penn State football program has been rife with changes over the last 10 months, from new coaches to altered histories to player departures.

Even the normal annual changes have left their mark with graduation taking away star players.

But here's a very promising sign for Nittany Lion football fans: The team lost a first-team All-American who was the Big Ten Defensive Player of the Year and a second-round NFL draft pick, and the defensive line should be just as good as it was in 2011.

"That's really the strength of our football team with the linebackers," new head coach Bill O'Brien said last week. "The front seven's the strength of the football team."

The Nittany Lions have size, talent and depth with their defensive front, and much will rest on its shoulders this year.

"I think we have more depth at this than we've had at any point during my career here," fifth-year senior defensive end Pete Massaro said. "We've got a lot of speed on defense and we've got a lot of aggressive guys."

The optimism begins with the starters -- three of whom are seasoned veterans. The team did lose starters Jack Crawford, Eric Latimore and All American Devon Still, who is now working in the trenches with the Cincinnati Bengals, but there shouldn't be a drop in production.

Returning are Massaro and Sean Stanley at the ends and defensive tackle Jordan Hill. Hill, the most seasoned of the linemen with 17 career starts, was sixth on the team last fall with 59 tackles, is a preseason All-Big Ten pick and figures to be a beast in the middle of the line.

"He's one of the best three-techniques in the country," linebacker Michael Mauti said. "He just eats blockers. He's so athletic -- 300-pounders should not move like that. Physically he's a freak. To have that in front of you makes you feel more comfortable."

The other defensive tackle starter will likely be DaQuann Jones, with depth provided by Deion Barnes, Brad Bars and Central York High School graduate Kyle Baublitz, who has moved over from defensive end.

They are all learning the schemes of new defensive coordinator Ted Roof, who has made a few tactical changes to the system.

"We return a lot of great players, talent-wise," Stanley said. "We're accepting Coach Roof's style of play. We really like his aggressive style. We're looking forward to what we've got on Sept. 1."

So what kind of specific changes can fans expect? The players were rather coy with their answers.

"I guess we'll see when we come out against Ohio," Massaro said. "I can tell you it's going to be fun to watch."

"It's pretty much the same overall scheme," Stanley said. "We're allowed to play a little bit more aggressively as a defensive end. They want pressure upfield on run, which helps us transition to pass rush."

The changes have provided a few challenges, but the players are eager to put what they've learned to work in the season opener against Ohio.

"We're still learning a lot of new stuff," Hill said. "You can't do everything in spring ball that you want to do for the season."

The hardest part has been erasing some of their knowledge from years past -- and it has been tougher on some more than others.

"Every once in a while I find myself using words I've said in the past that meant the same thing, but different things," said Larry Johnson, who is entering his 17th season as defensive line coach and is one of two holdovers from Joe Paterno's coaching staff. "You kind of catch yourself. I do my homework. I go home and study."

Other than vocabulary, though, Johnson doesn't think the defense will be that different from years past when Penn State was frequently among the nation's statistical leaders.

"It's just the same kind of stuff, just different names, different whistles and bells," Johnson said. "It's not all that different. We're still a four-man front base. ... When we call something this, he calls it that. It's just terminology."

Massaro is especially eager to hit the field for the opener as he returns from a torn ACL suffered in the spring of 2011 and forced him to miss all of last season. He said he has ditched the brace and feels faster than he did before the injury.

"The motor's better now," Massaro said. "I'm going to be like a bat out of hell on that field this year."

The Nittany Lions hope the feeling is the same throughout the entire defense, which lost only one key player after the NCAA allowed unfettered transferring from the program in late July. Other than normal attrition, the unit has stuck together and gives the program the strength it needs.

"This place has been known for great defenses and we really want to continue that tradition," Massaro said.

"We've going through a lot," Hill added. "I really feel it's made us closer as a defense, not only on the field but off the field."