Philadelphia Eagles quarterback Carson Wentz was ruled out of the remainder of the season after suffering a torn cruciate ligament, coach Doug Pederson confirmed Monday.
Wentz, 24, the driving force behind the Eagles' 11-2 season which has seen them emerge as one of the favourites for the Super Bowl, was injured in Sunday's 43-35 win over the Los Angeles Rams.
The quarterback was hurt after taking a big hit as he attempted to dive in for a touchdown which was called back for a penalty.
Wentz hobbled out of the game soon afterwards having thrown for 291 yards and four touchdowns in another stellar display.
He will be replaced by back-up Nick Foles for the remainder of the campaign.
"The reason we went out and got Nick Foles are for reasons like this," Pederson told reporters on Monday. "I hate it for Carson, and the season he's having."
The Eagles wrapped up the NFC East divisional crown with Sunday's win over Los Angeles.
Philly now face the New York Giants this Sunday before a Christmas Day game against the Oakland Raiders.
They complete their season against the Dallas Cowboys on December 31.