The Detroit Lions had everything going on Sunday in a blowout 47-9 win at the Dallas Cowboys, but then suffered what looks like a big loss.

Defensive end Aidan Hutchinson, Detroit’s best defensive player and candidate for the NFL Defensive Player of the Year, was injured in the second half on a sack by Cowboys quarterback Dak Prescott. He winced in 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.

Lions head coach Dan Campbell confirmed after the game that Hutchinson will undergo surgery for a broken leg and will remain in Dallas to get that done. A specific timeline for his recovery is unknown. The Lions confirmed after the match that Hutchinson suffered a tibia injury, but it was not a compound fracture as initially thought.

“He’s in good hands now,” Campbell said. “He’s being taken care of… Obviously he won’t be active for a while. So that’s tough, man. It’s hard when you lose someone like him.’

On Monday, the Lions announced that Hutchinson had undergone successful surgery to repair a broken tibia and fibula. He returns to Detroit this week and is expected to make a full recovery, but there is currently no timeline for his return to play.

The Lions led the 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.