OXNARD, Calif. -- Saturday's Dallas Cowboys training-camp practice sounded different.

Above the whistles and horns signifying the beginning and ending of drills and the yells from the fans along the sidelines, there was Sean Lee running through what was like a play-by-play for his defense. As the offense broke the huddle, Lee immediately barked out signals. As Dak Prescott made his calls, Lee had answers.

He was talking almost until the moment the ball was snapped.

"All the time, he's talking," defensive coordinator Rod Marinelli said. "He's just prepared. I think it's a great feeling for the defense when you hear his voice. He knows the calls, the checks. He's been there, done that."

Lee missed the first eight padded practices of training camp, and the Cowboys look to break the veteran linebacker in slowly. The goal is to make sure he is as close to 100 percent as possible for the Sept. 9 regular-season opener at the Carolina Panthers.

Lee's importance to the defense cannot be overstated. He missed five games last season because of two hamstring strains, not including three-plus quarters of action in the loss to the Atlanta Falcons -- and the defense was lost without him.

In the five games without Lee, the defense allowed an average of 21.2 first downs, 386.4 yards, 135.2 rushing yards and 25.8 points per game. In the 11 games with Lee, the defense allowed an average of 18.7 first downs, 287 yards, 89.8 rushing yards and 17.4 points per game.

"That guy, he runs the field," defensive end Tyrone Crawford said. "He runs the field. He's the general. They call him that for a reason. Our confidence is at a level higher than everyone can see. It's blatant. It's definitely great to have him back. We want him to get as healthy as he possibly can. We're not mad when he sits out. We just want him to be 100 when he comes back for sure."

A sense of guilt overcomes Lee when he is out. Injuries have been the story of his career -- hamstring, wrist, toe, neck, knee and a concussion -- costing him 41 games. In 2015, he played in 14 games. It would have been 15, but he pulled himself out of the lineup in the finale of a forgettable 4-12 season. In 2016, he dressed for every game, with the coaches holding him out of a meaningless season finale after the Cowboys already had clinched home-field advantage in the playoffs.

"You want to be out sharing every sacrifice with your teammates," Lee said. "Sometimes I have to change that because of some of the injuries I've dealt with, but hopefully going forward, I'll be involved as much as possible."

While he has taken part in just three padded practices here, his presence has still been felt. He has quizzed first-round pick Leighton Vander Esch during practice. The rookie linebacker said he could not have come into a better situation than to learn from Lee.

"[He's] an animal. He really ramps it up when he gets on the field, even off the field. I mean the dude is just intense," Vander Esch said. "But actually seeing him in person and experiencing how he is is a whole another level than just knowing that, 'Hey, that dude is an intense guy.' You've got to experience it in first person to actually know."

Lee is not afraid to call out the defense after a poor play or mental mistakes. He is not afraid to call out himself. At the conclusion of Saturday's walk-through, he let loose with three F-bombs, upset with how he read a certain situation.

"I can understand everything he's saying," said Marinelli, who has been known to let the expletives fly. "That's what we love about him. In his mind there's no walk-through. It's a game. The pace, it's just slowed down."

It did not take Lee long to get involved in his full practices. He can see things quicker than most linebackers, greeting Ezekiel Elliott in a hole or finding a tight end in the flat. And if he doesn't get there or if another player isn't in the right spot, Lee will let everybody know. Loudly.

"Certain guys who are in those leadership position on offense, defense and in the kicking game -- some guys bring it from down here, and you hear them more," Cowboys coach Jason Garrett said. "Sean certainly has great conviction about stuff. He really knows what he's doing, and he's not afraid to bark it out and make sure everybody's on the same page."

Lee wants to see some action in some of the final three preseason games. He believes he needs the action to get up to speed for the regular season, even if he plays 20 to 25 snaps. If not, he will listen to the coaches and medical staff.

There is just one goal.

"We have a game plan," Lee said. "Two years ago, in '15 and '16, it worked really well. Last year, not as much. We adjust on the fly, and hopefully it will improve as I go and it will lead to me staying healthy. That's hopefully how you quantify it -- 16 healthy games."