A big story of the offseason was the NFL eliminating the hip drop tackle, a dangerous play that led to some high-profile injuries.

The problem, perhaps, is that it’s tough for officials to identify what is a hip drop tackle in real time.

There have been some plays that were not called that appeared to be hip drop tackles. Buffalo Bills quarterback Josh Allen thought he was the victim of one in Week 1 and argued with the officials, but didn’t get the call. Cincinnati Bengals receiver Ja’Marr Chase argued with officials after a tackle, getting a 15-yard penalty, and he might have been upset that a hip drop wasn’t called. Chase didn’t comment after the Bengals’ loss to the Kansas City Chiefs.

And the play in which Houston Texans running back Joe Mixon was injured on Sunday night sure looked like the type of play the NFL said would be penalized this season.

Mixon was dragged down, his foot pinned underneath him, by Chicago Bears linebacker T.J. Edwards. It looked like a textbook hip drop tackle. Mixon limped off the field and was taken to the locker room. No flag was thrown.

Mixon did return to the game shortly after, and he was lucky the injury wasn’t worse.

It’s hard to look at that play and not think it was the outlawed hip drop tackle. Both NBC announcers on the Sunday night broadcast thought it was.

“The wrap, both legs swinging off the ground and in the back of the leg,” NBC color analyst Cris Collinsworth said.

“Wrap, swivel, unweight, land on the legs,” play-by-play announcer Mike Tirico continued. “Those are the four indictors all together that make that hip-drop tackle they’re trying to take out of the game. All four of those indicators there on that play. So hard for the officials to call live on the field. But something that is fineable later in the week.”

It’s hard to identify all the mechanisms of a hip drop tackle given the speed of the game. But it was added to the rulebook for a reason, and officials need to be able to spot it when it happens. It wouldn’t have helped Mixon and his injury, but perhaps it would discourage it in the future, which was the NFL’s intent.