When NFL officials visited Bears camp to show a film on rule changes aimed at player safety, inside linebacker Danny Trevathan realized he'd have to alter his style.
"Shoot," Trevathan said. "I was on the film."
One of last season's most physical and controversial plays landed Trevathan a one-game suspension, and joined several other incidents of brutality in causing the NFL to curtail the use of helmets in tackling.
Trevathan's helmet-leading hit knocked Green Bay Packers wide receiver Davante Adams out of a Sept. 28 game and resulted in a two-game suspension — later reduced to one on appeal.
Possibly more than any other Bears player, Trevathan must now keep his physical, aggressive style in check.
"I've got to be able to move on from it and learn the new techniques," Trevathan said. "The game is constantly changing. That's what we get paid to do, I guess. I've got to take that in my play."
Bears defensive coordinator Vic Fangio believes it's a matter of accepting change for all defensive players, and eventually they'll adjust as with other rules.
"One of the most non-football rules ever put into football was the 5-yard illegal contact rule," Fangio said. "If coaches from the 60s rose from the dead today they would want to go back in their grave with that rule.
"And we've adjusted."
Bears coach Matt Nagy is seeing signs of Trevathan controlling his play.
"There's a leadership element, which goes without saying," Nagy said. "There's a physicality that he brings."
The Bears had what Nagy called their most physical practice of camp Sunday, complete with a full-contact red-zone period. And Nagy noticed Trevathan pulling back at one point when he could have easily smashed rookie wide receiver Anthony Miller.
"There was a play today where he could have knocked (Miller) into the stands and he decided not to, and that was in a live period," Nagy said. "So to me, when you see that, I'm going to point that out to the team tonight because that wasn't stupidity. That was a veteran being smart, not taking out one of our guys.
"He knows it's live, he knows he doesn't have to prove anything, so just play smart."
Trevathan also views playing under control as a benefit to his own health. This is important because Trevathan has missed 10 games the last two seasons due to injuries, and the defense suffered then without its field general.
The effect on the Bears' defense without him is obvious.
In 2016, the Bears allowed 152 yards rushing a game without Trevathan starting seven games, and 98.4 yards in nine games when he started. Last year they allowed an average of 97.5 yards rushing in 11 games with Trevathan and 140 yards a game in five without him.
"It's imperative that I be on that field," Trevathan said. "I'm not going to let my team down anymore. That comes with a responsibility: just taking care of yourself.
"You know plays happen; you get injured. It's only going to make the defense better when I'm out there because I'm going to push and I'm going to work my tail off and I'm not going to let anybody beat me."
Like the rest of the Bears, Trevathan watched former Bears middle linebacker Brian Urlacher get inducted into the Pro Football Hall of Fame over the weekend. Trevathan gained insight from Urlacher's speech, particularly in regards to overcoming adversity and being a good teammate.
"That's one of the main reasons why I came here — the tradition at linebacker," said Trevathan, who left Denver as a free agent after 2015. "It's not an easy job, but like he (Urlacher) said, it's like the tough stuff makes you grow.
"I'm here for a reason, and I like playing linebacker for the Chicago Bears."
NOTES: Wide receiver Taylor Gabriel missed Sunday's practice after suffering a foot injury in Saturday's session. Nagy called it "day to day" and not serious.