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

Defensive end Aidan Hutchinson, Detroit’s best defensive player and a NFL Defensive Player of the Year candidate, injured himself on a sack of Dak Prescott. He winced in obvious pain as he wrapped up Prescott, then stayed down. A cart came on the field for him.

The replay showed that as Hutchinson spun around while wrapping up Prescott, his leg hit a teammate. The force of the blow caused what looked like a broken leg for Hutchinson. Players from both sides came on the field as Hutchinson was being loaded on the cart, and an air cast was put on his injured left leg.

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 have looked like one of the best teams in the NFL. But losing Hutchinson for a while would severely impact their hopes of making the first Super Bowl in franchise history.