While Julius Peppers owns the title of oldest Chicago defender, the seven-time Pro Bowl defensive end spends little time dwelling on how many more years he has left in the NFL.
"I feel like I'm 25," the 33-year-old Peppers said. "Age is just a number that people put on players. It's really in your heart and your mind how you feel. I think it's been showing."
Coming off his highest sack total (11.5) since 2008, Peppers plays on a line younger through attrition after the departure of Brian Urlacher (retirement) and Israel Idonije (to Detroit). Four starters are 30 or older, but Peppers doubts the defense will show it.
"That's the thing in this league," Peppers said. "When you reach 30, that's the number that everybody wants to put on you and say you're getting old. But these guys come out and work hard.
"We all know what we're doing. I think we've got the right mix of older guys and younger guys. I don't think it's a problem as far as age on this team."
If Peppers feels like he's 25, teammates see someone even younger.
"A guy that's 24," said defensive tackle Henry Melton. "He looks good. He's moving well. He hasn't lost a step."
The Bears defense has been bothered by injuries in training camp. Peppers enter his 12th season healthy after playing through nagging injuries the last two seasons. He was bothered by a foot injury last year and a knee injury in 2011.
When Peppers came to Chicago, a reputation for taking occasional downs off followed him, despite making big plays. That distinction disappeared long ago. He's amassed a career sack total if 111.5, second only to Jared Allen among players who came into the league in 2002 or later.
"He's just a role model for the younger guys, for guys like me and for veterans who just go out there and see him working," Melton said. "He doesn't take a day off unless the coach makes him take a day off."
Some of the spring in his step comes from playing fewer downs last year than in his first two seasons with the Bears. With Corey Wootton and Shea McClellin also at defensive end, Peppers expects to be rested enough again this season.
However, Wootton is sidelined with a hip injury and Turk McBride, brought in for depth at the position, is out for the season with a torn Achilles tendon.
Rookie Jonathan Bostic is playing middle linebacker for injured D.J. Williams, who is bothered with a calf strain.
"It's going to be week to week and these things happen during training camp," new Chicago coach Marc Trestman said.
The Bears are glad to have veteran Peppers to carry the defensive load until healthy players return.
"The way he carries himself around the locker room through the meetings and certainly on the field, and watching him since April, it's just impressive, the consistent high level of effort," Trestman said. "He's all over the field. He's first in line.
"We all want to grow up and be like Julius."
NOTES: The Bears signed tight end Leonard Pope, who has played for St. Louis, Kansas City and Pittsburgh. The 6-foot-8, 264-pounder has 105 career catches for 982 yards since coming into the league in 2006. ... Tackle Jermon Bushrod shed the soft cast on his right calf after suffering a calf strain last week, but remains out of practice. With backup tackle Jonathan Scott out with a knee injury, J'Marcus Webb has shuttled between right tackle and left with backup Eben Britton.