Minnesota Vikings starting quarterback Teddy Bridgewater suffered "a complete tear to his ACL and other structural damage" on Tuesday in practice, the team announced.
An ambulance pulled up to Minnesota's training facility shortly after the injury, which was cut short after about 30 minutes. Bridgewater will now miss the entire 2016-17 season.
"The injury was stabilized, and he was transported to a nearby hospital for treatment and evaluation," said Vikings Director of Sports Medicine and Head Athletic Trainer Eric Sugarman on Bridgewater.
"After undergoing an MRI, it was determined that Teddy suffered a complete tear to his ACL and other structural damage. Fortunately, there appears to be no nerve or arterial damage.
"Surgical repair will be scheduled within the next few days. Although the recovery time will be significant, we expect Teddy to make a full recovery. I would like to thank all of the medical professionals and our athletic training staff for all of their help today.
"Teddy has already displayed the attitude needed to overcome this injury and attack his rehab."
Bridgewater started all 16 games last year while leading the Vikings to the post season. He completed just over 65 per cent of his passes with 14 touchdowns and nine interceptions. He also rushed for 192 yards and three more scores.