The tackles that injured Chiefs quarterback Patrick Mahomes and Cowboys running back Tony Pollard during the playoffs were legal. But they may not be next season.

Dr. Allen Sills, the NFL’s chief medical officer, said today that the techniques used on those tackles, in which the defender grabs the ball carrier from behind and then pulls him down while dropping the tackler’s own body to the ground, could be eliminated. That type of tackle, known in rugby as a “hip-drop tackle,” was banned by the National Rugby League in Australia because of the injuries it caused.

“I think it’ll be a very active offseason conversation, to look at the mechanism.