"Number 1, we have to remember why we are in the position we are in and have to understand our responsibility to the community, children and child abuse organizations," O'Brien said. "That is No. 1, and these kids understand that."
O'Brien was the only member of the team to speak to the press on Monday. Penn State's media day will be Thursday.
The first-year coach is adopting a new openness at Penn State that was demonstrated by the fact that the media was allowed to watch the last 30 minutes or so of practice.
Practice began at 6:15 a.m. on Monday, and O'Brien chided himself for arriving a little late even though he arrived an hour and a half before the first workout
"I got here about 4:45 and couldn't wait, couldn't sleep last night for good reasons because I couldn't wait to start practice," O'Brien said. "Our whole staff was here before me, and I think I was the last to arrive."
The staff got there at 4:30.
"They will be busting my chops," O'Brien said in one of the lighter moments of the press conference.
Players can still transfer, but O'Brien said he is confident that the team he has assembled will stay together. Nine players have left, and two recruits in the 2013 class have also decided not to attend.
"At the end of the day I feel really good about keeping this team together," O'Brien said.
He didn't criticize those who have departed.
"I know some guys left, and that is OK. That was their individual decision," O'Brien said. "We respect that decision, but we are moving forward with this team."
In the opening practice, which was carried out at a crisp pace and mirrored NFL workouts, the Penn State incoming freshmen were held out. O'Brien wanted them to get acclimated, and they were to work out together Monday evening.
On Tuesday, the freshmen will work out with the squad.
As for the team's health, O'Brien said at this point there were no serious injuries. An estimated 83 players participated in the opening workout.
"I feel really good about the depth in most positions," O'Brien said. "In the secondary, we are a little thin now based on numbers. But those guys are out here competing, and I feel good about where we started today, and we have to keep getting better every day."
O'Brien said he was pleased by the continued progress of senior Matt McGloin, who has been appointed the starting quarterback. Another player who has impressed the coach is Bill Belton, the sophomore from Winslow Township High who is moving from receiver to running back.
A former Inquirer South Jersey offensive player of the year, Belton broke some impressive runs in the opening practice.
His role is even more important since Silas Redd transferred last week to USC. Redd rushed for 1,241 yards (5.1 average) and seven touchdowns.
"Bill Belton is a good football player, and he was going to play this year [regardless]," O'Brien said. "[Losing Redd] definitely affects the depth, but we are not retooling everything because one player left. This is about a whole team and not one player."
O'Brien kept emphasizing the team aspect and how his players have stuck together, and he said it will be an easy group for the fans to support.
"I expect our fans to really root for this football team because this is a good bunch of kids that care about playing football for Penn State, that care about getting a degree from Penn State," he said. "So I expect our fans to turn out and to embrace the new era of Penn State football."
Contact Marc Narducci at 856-779-3225, mnarducci@phillynews.com or @sjnard on Twitter.