Packers personnel examine Davante Adams Thursday night after a hit by the Bears’ Danny Trevathan. (Matt Ludtke/AP)

NFL referees have the power to eject players for violent, illegal hits to the head. This offseason, the NFL emphasized this power, reminding officials in writing that “egregious” hits to the head should lead to automatic and immediate disqualification. To reduce dangerous plays, players need incentive, and the NFL’s point of emphasis provided it.

Thursday night provided horrifying evidence the NFL needs to do more. In the third quarter of the Green Bay Packers’ shellacking of the Chicago Bears, Aaron Rodgers passed to wide receiver Davante Adams over the middle. The Bears had Adams wrapped up, spinning to the ground.

At full sprint, linebacker Danny Trevathan lowered his head, leapt from his feet and smashed into Adams’s face mask with the crown of his helmet. The hit was purely unnecessary violence. It did nothing to further halt Adams’s progress, because he had been stopped. It only served to hurt and potentially injure Adams.

Adams’s mouthpiece flew. As he lay still on the ground, players on both teams waved for trainers. Medical personnel strapped Adams to a board, carried him off the field and placed him in an ambulance. The Packers later tweeted that Adams was conscious, had feeling in all extremities and had been taken to a hospital for further testing.

Trevathan’s dirty, illegal hit went far beyond “egregious.” He will surely be fined, and former head of officials Mike Pereira said on Twitter he would suspend Trevathan. But officials allowed Trevathan to finish the game.

If a referee’s interpretation of the rule made it possible for Trevathan to finish the game, even if the league decides it was the wrong interpretation after the fact, the rule needs to be changed and made stronger. The point of emphasis was a good idea. In practice, we now know it wasn’t enough.

There is a ready-made model the NFL can use. The NFL should borrow from, if not outright duplicate, the collegiate targeting rule. When a player is called for an illegal hit to an opponent’s upper body, he is flagged 15 yards and ejected; if the hit happens in the second half, the offender also misses the first half of his next game. All targeting calls are reviewed on replay, to ensure an innocent tackler or blocker isn’t thrown out.

The college targeting rule prohibits “forcible contact to the head or neck area of a defenseless opponent … with the helmet, forearm, hand, fist, elbow or shoulder.” For the call to be made, the hit must include the defensive player launching, leading with his helmet or lowering his head before attacking with the crown of his helmet. Defenseless players can be one who’s just thrown the ball, caught a pass or tied up by other tacklers, just kicked, just caught or about to catch a punt, on the ground, obviously out of play or being blocked from his blind side. The rule also states, “when in question, it’s a foul.”

The NFL can tweak the language. But the example Trevathan provided demonstrates the need for a similar system in the NFL. Had referees automatically reviewed Trevathan’s hit, they would have seen the clear egregiousness and ejected him. In real time, they threw a flag that, because it happened near the goal line, cost the Bears only four yards.

Fines, and even the threat of suspension, are not enough to dissuade players from dangerous hits. They are wired to win in the moment. A greater chance of suspension enforced by clearly written rules, as opposed to in-the-moment interpretation by officials, would help. The college rule can be frustrating, but it has led to fewer illegal hits. That’s a worthy trade-off.

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