Jon Bostic wasn't even penalized for the de-cleating he administered to San Diego's Mike Willie last week that broke up a short pass intended for the wide receiver and fired up the Bears' defense.
But the rookie linebacker was notified Wednesday morning that the NFL had fined him $21,000 for the hit.
Although the second-round pick from Florida received a $1.25 million signing bonus, his base salary this season is $405,000.
So the fine amounts to slightly less than the $23,828 of each of his 17 weekly checks once the regular season begins. And he hasn't even received the first one yet.
Bostic is just the latest player to run afoul of the league's attempt to legislate violence out of the game, and his teammates came to his defense.
"The league thought that it was an illegal hit; I disagree," 11th-year linebacker Lance Briggs said after Wednesday's practice inside the Walter Payton Center.
"I think that if you ask around the league, probably 100 percent of the league's going to say it was a legal hit, but it's not my call."
Hours earlier Briggs was on Twitter, criticizing the fine.
"Shaking my head moment. Nfl fines jon bostic 21k for his clean hit against the chargers," he tweeted.
Although Bostic's hit separated Willie from the football and left the wide receiver flat on his back, there appeared to be no helmet-to-helmet contact.
Still, the league said Bostic was in violation of Rule 12, Section 2, Article 7 (b) (2), which deals with prohibited contact against a player who is in a defenseless posture.
It reads: "Lowering the head and making forcible contact with the top/crown or forehead/'hairline' parts of the helmet against any part of the defenseless player's body."
Most of those who watched and re-watched the hit had a major problem with the word "defenseless," since Willie took a step with the ball before he was blasted by Bostic.
Asked about the fine, Bears coach Marc Trestman said: "I don't have any reaction right now about anything. When I looked at it, other than to say that I thought it was a clean hit, his head was up, and he hit with the shoulder from my vantage point on the field.
"Looking at it on the tape, I thought it was a clean hit.
"It was a violent hit, no doubt about it. But I believe that it was in the frame of the rules."
Bostic has taken over as the starting middle linebacker in the wake of a calf injury that has sidelined D.J. Williams since the end of July.
The rookie seemed surprised by the fine but vowed to stay focused on Friday night's third preseason game against the Raiders in Oakland and on preparing for the season opener Sept. 8.
"I'm still trying to figure that stuff out," he said of the fine. "Obviously, I'm new to the league. I'm learning from the older guys and really just finding out the process."
Bostic is sure to appeal, and there is precedent for a favorable ruling. Safety Chris Conte had a $21,000 fine reduced to $11,000, and he believes Bostic has a case.
"I thought it was a clean hit," Conte said. "I think just because of the gravity of the hit, it was such a big hit, and obviously it looks like (Willie's) head jerked.
"But it's such a fine line, it's hard to really say, 'That's a legal hit; that's an illegal hit.' We're playing so fast, it's really a tough thing to judge, and it's too bad the fine is that expensive.
"That's a lot for a rookie. I mean, he got drafted in the second round, so he's got a little bit of money, but still it's a tough thing."
Bostic's fine raises bigger issues for all defensive players.
Where can you hit a ball carrier?
"The navel?" Briggs said. "There's not a lot of area to hit when you're playing at 100 miles an hour and you're told to react right now. One thing that you do know is that you can't hit in the head, neck, really in the chest area, so what does that leave?
What could Bostic have done differently in that situation?
"He could have allowed the receiver to run him over," Briggs said. "That's another technique. We could play the catch technique; we could take a charge. I don't know.
"You've got to play football, and that's what he was doing. None of the referees seemed to think there was anything wrong with the play.
"All I saw on the play was a receiver was coming in, full flow. Bostic with a head's up play, and not only did he make the hit, he jarred the ball loose."
That's what defenders always have been taught to do, but maybe the lessons need to change.
•Follow Bob's NFL reports on Twitter @BobLeGere, and check out his Bear Essentials blog at dailyherald.com/sports.