The NFL has enacted a rule to protect players by penalizing defenders who use the hip drop tackle technique in the open field.

Houston Texans running back Joe Mixon felt the referees missed the point in the third quarter of Sunday night’s game.

Mixon attempted to force his way out of bounds after a pass from CJ Stroud in the final seconds of the third quarter, but Chicago Bears linebacker TJ Edwards intercepted the ball. In the first film, Edwards drops his weight, causing Mixon to collapse under the pressure.

Mixon vented his frustration on Twitter, clarifying that he had contacted officials for a further response, but they did not consider this sufficient to impose a penalty.

He was listed as questionable for the 2021 Pro Bowl due to an ankle injury and went into the blue medical tent. He then left the field to return to the locker room for further evaluation. And although Mixon returned, it was only for seven games in the final three series.

“Joe got rolled over,” Texans coach DeMeco Ryans said. “The guy’s weight was clearly on his ankle. It didn’t look good from my perspective. We’ll evaluate Joe later this week. Hopefully he’s OK. I’ll have to look at the film to see if it was really a hip-drop tackle.”

Although the Texans won 19-13, penalties – both called and uncalled – were a problem. Houston committed 12 penalties for 115 yards, while Chicago was penalized nine times for 60 yards.

But the referees also missed plays beyond Mixon’s hip-drop offense. Texans linebacker Azeez Al-Shaair hit Bears running back Roschon Johnson but stayed in the game, even though NFL rules state that a player must be ejected for a physical altercation.

This isn’t the first time referees have stood back and ignored potential hip-drop tackles. Buffalo Bills quarterback Josh Allen thought Arizona Cardinals cornerback Kei’Trel Clark made such a tackle last week and argued with the referees after the game.

Shortly before kickoff in Houston, Cincinnati Bengals receiver Ja’Marr Chase argued with the referees after Kansas City Chiefs cornerback Trent McDuffie made a tackle in the open field. He received a 15-yard penalty and was visibly upset that no hip drop penalty was called.

Mixon’s departure didn’t hurt the Texans’ score, but it remained tight in the final 15 minutes. Houston needs Mixon as the lead back for its Week 3 game against the Minnesota Vikings, so his status is crucial to keeping the team afloat.

This article originally appeared on Texans Wire: Texans RB Joe Mixon tweets his frustration over tackle in Bears game