The Facts: Carlson could miss several weeks after spraining a knee in Tuesday's afternoon practice. The initial diagnosis is a sprained medial collateral ligament, HC Leslie Frazier said. "If that's what it turns out to be, you don't have to have any surgery," Frazier said. "It heals by itself. So, it's a little bit more of a pain tolerance thing, depending on how he feels."

Diehards Line:According to 1500ESPN.com's Tom Pelissero, Carlson was to undergo an MRI later in the day to make sure nothing is torn. Asked if the injury could sideline Carlson for a while, Frazier said, "It could. It could. We'll see. They'll tell me more when we get back in. But initially, that's what they told me -- sprained MCL. ..." Carlson, 28, signed a five-year, $25 million contract with the Vikings in March and is expected to play a major role in Bill Musgrave's multiple tight end offense alongside Kyle Rudolph. He sat out last season in Seattle with a shoulder injury. The other tight ends on the Vikings roster are Mickey Shuler, Allen Reisner and Rhett Ellison, the rookie fourth-round draft pick from Southern California.