The Detroit Lions had everything going smoothly on Sunday, but then suffered what looks like a major loss.

Defensive end Aidan Hutchinson, Detroit’s top defensive player and candidate for the NFL Defensive Player of the Year, injured himself during a sack of Dak Prescott. He winced in obvious pain as he wrapped Prescott up and lay there. A cart came onto the field in front of him.

The replay showed that as Hutchinson turned around wrapping up Prescott, his leg hit a teammate. The force of the blow caused what appeared to be a broken leg for Hutchinson. Players from both sides entered the field as Hutchinson was loaded onto the cart and an air throw was placed on his injured left leg.

WARNING: The replay on Fox is graphic.

The Lions led the Dallas Cowboys 34-6 at the time of Hutchinson’s injury. They were on their way to improving to 4-1 and looked like one of the best teams in the NFL. But losing Hutchinson temporarily would have a serious impact on their hopes of reaching the first Super Bowl in franchise history.