Ross Tucker thinks the Vikings will miss Matt Birk more than the Vikings think they'll miss Matt Birk (Sports Illustrated). I think good teams with good quarterbacks can replace a center without losing much (though the Vikings may not be a good team and probably don't have a good quarterback). I'll cite two examples (as anecdote, not evidence): the '94 12-4 Cowboys replaced Pro Bowl center Mark Stepnoski with Ray Donaldson, and the '95 Cowboys went 12-4 and won the Super Bowl. And the '99 Vikings went 10-6 and ranked 5th in scoring (24.9 ppg); they replaced Pro Bowl center Jeff Christy with, oh yeah, Matt Birk; the '00 Vikings went 11-5 and ranked 5th in scoring (24.8 ppg). Perhaps losing a player doesn't matter quite so much as the quality of the player you replace him with. Or perhaps quality teams can make replacement centers look good.
Don Banks' fifth mock draft: Vikings take WR Kenny Britt (Sports Illustrated). I'd like to see a new defensive back.