CHICAGO — When does football cease to be football?

In an NFL summer dominated by controversy over the new helmet rule — which, by the way, hasn't been as much of an issue in the third week of the preseason, days after the NFL's important clarification on inadvertent contact not being flagged — we interrupt that handwringing to shine a light on the other rule change geared toward improving player safety.

Chiefs second-year OLB Tanoh Kpassagnon was flagged 15 yards for roughing the passer following a form tackle resulting in a sack of Chase Daniel late in the second quarter Saturday.

"I had my little celebration after it — first sack of the preseason — so I was just excited," Kpassagnon said in the visitors' locker room following Kansas City's 27-20 defeat courtesy of the Bears in the third preseason game. "I didn’t even know the flag was on me. I was looking around and found out it was on me."

On the play that was deemed illegal by official Clete Blakeman's crew, Kpassagnon blew past the outside shoulder of Chicago Bears RT Rashaad Coward before delivering a hard, albeit clean, hit into Daniel's chest. Tanoh kept his helmet up and saw what he hit. He led with his shoulder. He was flagged anyway.

The NFL is now penalizing players who fall on quarterbacks, the new "Anthony Barr rule," after the Minnesota Vikings linebacker broke Green Bay Packers QB Aaron Rodgers' right collarbone on a similar play last year.

"I know what I did," Kpassagnon said. "... I think it was just landing on him with the tackle. I don’t know."

That makes a lot more than two of us who are puzzled by it.

"I guess they kind of want me to do something that a lot of people think is physically impossible," he said, laughing.

Kpassagnon's penalty Saturday isn't the first called under this enhanced rule that has many football fans at their wit's end. Jets OLB Jordan Jenkins crushed Alex Smith early in the preseason opener with what appeared to be an avoidable body slam, and Vikings LB Antwione Williams planted Jaguars QB Cody Kessler last weekend in a flag-inducing hit similar to Kpassagnon's, both setting social media ablaze.

Kpassagnon, a 6-7, 290-pounder, admitted he might be at a disadvantage when he's destroying a 6-0, 225-pound passer like Daniel purely from an optics standpoint. And he said he's all for player safety, and that he understands the referees are doing their best in an almost impossible situation.

But it isn't the new helmet rule, he said, that could make for the most difficult adjustment for defenders across the league.

"Helmet rule, it’s just keep your head up," he said. "We’ve all been taught it’s safer for both players — I understand safety of the game. Everybody wants to keep their head safe, their body completely [safe]. It’s a lot harder than just the helmet rule, on both sides, calling it and trying to fix it.

"Still, football is football."

Added Daniel when asked about the hit: "I've got to go back and watch it. To me, that's a judgment call, right? There's definitely some things in preseason that these refs and umpires are watching for. That is one of them, the bodyweight rule or whatever you want to call it. ... But I mean that's football. It's physical."

How much longer will it be recognizable?