And yes, he's young, but what people are forgetting is that Birk was once unproven too. He became the Vikings starting center in his third year, replacing Pro Bowler Jeff Christy, who had signed with the Buccaneers. And everyone was worried about the young, unproven Birk taking over for the experienced Christy. Of course, everyone had forgotten that Christy had been unproven when he became the Vikings' starting center in his second season.
And let's not forget--the Vikings' line wasn't that great last year. According to Football Outsiders, they were only 15th in adjusted line yards and 28th in Adjusted Sack Rate. And while Birk played well last year, the Vikings still had trouble running the ball up the middle, finishing 19th in rushing yards on runs between the guards.
So if the Vikings' think Sullivan can step in for Birk and play as well as he did last year, that's good enough reason for me not to be too worried. As Kevin Seifert points out, if they'd wanted to extend him, they would have done so earlier. I'd feel a little better if they had found a better right tackle in free agency (which at this point likely will have to happen through the draft, though there are some short term solutions available) so that Ryan Cook could back up both center and right tackle, rather than start, but that hasn't happened yet. Either way, the Purple were going to have to replace Birk at some point, which is why they drafted Sullivan last year.
More on Birk's signing:
- John Sullivan speaks with Access Vikings
- Joe Flacco is excited to play with his new center
- Randball chronicles the timeline of Birk's free agency