Star quarterback Aaron Rodgers suffered a suspected Achilles injury on his New York Jets debut against Buffalo Bills.
The NFL's four-time Most Valuable Player, who joined from Green Bay Packers in the off-season, was injured in the first quarter after being sacked by Bills defensive end Leonard Floyd.
"We're concerned with his Achilles," said Jets coach Robert Saleh. "It's not good."
The Jets won 22-16 in overtime at MetLife Stadium in New Jersey.
Rodgers arrived at the Jets amid much excitement as the franchise look to end the NFL's longest play-off drought of 12 years.