Josh Sweat couldn’t believe what he was seeing.

Sweat had become accustomed to watching injured Eagles veterans Fletcher Cox, Nigel Bradham, and Brandon Brooks run extra sprints during training camp practices. He’d gotten used to seeing them stay after practice to get in extra work. But here was Brooks, a Pro Bowl right guard, taking turns in post-practice technique work ... with Sweat and the other defensive ends?

“I saw them over there doing their drills, and, obviously, I’m not a defensive end,” Brooks said with a laugh. “It was just something else, extra, I could do. So I said, ‘Let me go do this.’ ”

Cox and Bradham have similar stories. All three missed the preseason, but all three begged the athletic training staff to let them run extra; to batter a blocking sled; to make believe they were playing while they were watching. You hear a lot about leadership. Well, this is leadership defined ... tangible ... real.

Cox, Brooks, and Bradham will combine to make about $30 million this season, and have made more than $133 million in their careers. They have Super Bowl rings, they have money, they have good reputations. They just want to win. To do their jobs.

That might sound familiar. Might even have a New England ring to it.

“It’s just building a winning culture. I think the Patriots do a good job of that, for example,” Brooks said. “We’re here to win. There’s no excuses. No bull----. No inner locker room fighting. If you come here, you’re going to work hard, and be a brotherhood.”

Cox had offseason foot surgery. Bradham had toe surgery. Brooks ruptured his right Achilles tendon in New Orleans on Jan. 13, perhaps the most catastrophic of the injuries, but not only did he start the Eagles’ opener Sunday, he ranked fifth overall and third in pass blocking among all NFL guards in Week 1, according to profootballfocus.com.

“It’s unbelievable, man,” said right tackle Lane Johnson. “Somebody that size, seven months from surgery, out there playing? He just kinda came off the couch and played. He’s a beast.”

Indeed, Brooks was a 6-foot-5, 335-pound, 30-year-old marvel. He allowed no sacks, no pressures, no hurries. The medical staff, in an abundance of caution, made him exit after 55 of the 75 snaps; could he have finished the game? “No doubt,” he said. “No problem.”

For his part, Bradham was disappointed that the defense only got to play about 10 minutes in the second half.

“I felt like I could’ve played another couple of quarters,” he said. Little wonder, considering his supplemental efforts.

While the rest of the defense scrimmaged the offense in July and August, Bradham simulated plays on the side, in a rather masochistic manner: He put on a black, hooded sweatshirt, his helmet, and full pads, and in a 95-degree heat, he would get into his stance, sprint 15 or 20 yards at a time -- at 45-degree angles, at 30-degree angles, straight ahead, sideways. He’d rest for 10 seconds, pretend to call a play, then he’d do it again. And again. And again, 15 minutes at a time.

Then, at the end of the day he’d volunteer for a grueling conditioning test.

“I knew the trainers would want to take care of me and make sure I was not overworking, but it’s different for a linebacker. I’m always chasing the ball,” Bradham said. “I knew I’d have to do more than what the plan called for.”

Bradham participated in just two full practices, but on Sunday he not only played every defensive snap, he led the team with seven tackles. Third-year linebacker Nate Gerry took note.

“Like you said, they’ve made their money and whatnot,” Gerry said. “You see that, you understand how they made it.”

Nobody has made more cash than Cox, the undisputed leader of the defensive line, who, like Brooks, usually didn’t head to the locker room once practice was done. He exited Sunday with a tackle for loss, two quarterback hurries, and even greater admiration from his younger teammates.

“That was all the time,” Sweat, a second-year end, said of Cox’s in-practice running and his post-practice drills. “Shoot; I started getting extra work after practice, too. It makes me want to get more and more conditioning. There’s no stopping, even when you’re already on the top.”

Staying on top is always harder than getting there. It takes extra effort -- effort these Eagles were willing to give.

“That,” said Brooks, “is the culture we’re trying to build."