Vikings quarterback Teddy Bridgewater suffered a "significant knee injury" at Tuesday's practice, coach Mike Zimmer said.
Bridgewater left Winter Park in an ambulance after a left knee injury that occurred away from contact.
Zimmer said he had no timetable for Bridgewater's return, but said "it doesn't look good right now" when asked if Bridgewater would play again this season.
"We'll let you know tonight or tomorrow, as soon as we find out the extent of it," Zimmer said at a news conference.
Zimmer said Bridgewater had been sedated and was getting an MRI on the knee. As reporters pressed him for details, Zimmer said, "Let's let him get taken care of please. I love this kid. Our fans love the kid."
The Vikings have a preseason game on Thursday night before opening the regular season on Sept. 11 at Tennessee.
"You know what, it's still about the football team," Zimmer said. "We're going to figure out the very best way we can beat a team that we play that week. If it's running it 65 times or throwing it 65 times, it still doesn't matter."
When asked about moving forward with a pall cast over his team, Zimmer said, "My wife passed away seven years ago. It was a bad day and the sun came up the next day.
"We're not going to stick our heads in the sand. We're going to find a way."
