Cook has been a solid contributor in a secondary that ranks No. 12 in defending the pass, so it could be a big loss for the Vikings.
The 25-year-old former second-round pick from the 2010 NFL Draft was injured during the second quarter of Thursday's game. He was taken to the locker room during the contest, and X-rays revealed a broken wrist. No timetable has been given for his return.
Rookie defensive back Josh Robinson replaced Cook during the game, and A.J. Jefferson filled in at the nickel spot. That leaves a lot of young players in the secondary, which worries Antoine Winfield (via the National Football Post).
"They need to step up now," Winfield said of the youngsters. "I don't know how long Chris will be out. Broken wrist, that's not good. But our motto is when somebody goes down, it's the next man up."
The Vikings face the Seattle Seahawks in Week 9.