HOUSTON -- When the Houston Texans take on the Vikings in Minnesota on Sunday, they will have to do it without their starting running back.

Joe Mixon was injured in last Sunday's primetime win over the Bears and didn't practice all week. On Saturday, the team said he did not travel with them for their game against the Vikings.

Mixon's ankle was hurt in what he said was a hip-drop tackle, something that was banned by the NFL before the season.

For the Texans, depth at running back is pretty shallow. Aside from Mixon, running back Dameon Pierce is out for Sunday with a hamstring injury, meaning Cam Akers should get the start. They can also put in British Brooks or Dare Ogunbowale.

So what is a hip-drop tackle? According to the league, it's when "...a defender wraps up a ball carrier and rotates or swivels his hips, unweighting himself and dropping onto the ball carrier's legs during the tackle."

So far, no discipline has been handed down to Bears linebacker T.J. Edwards, who tackled Mixon. The league is reportedly reviewing it. A flag wasn't thrown.

You can watch Sunday's Texans-Vikings game LIVE on KHOU 11 at noon. Then after the game, we'll stream the postgame news conference live on KHOU 11+ on Roku, FireTV and AppleTV.