Now that the Vikings' roster is finalized, we can spend a little more time analyzing it and looking at how the 2013 team was built.

I'm going to borrow from a couple of our former divisional bloggers who are graduating to national status -- Mike Sando and Kevin Seifert -- and with good reason, because both of them offered their usual sharp analysis this morning.

Jared Allen is one of four projected Vikings defensive starters this season who are 30 or older. Adam Bettcher/Getty Images

In ranking the ages of all 32 teams, Sando had the Vikings as the 15th youngest, which puts them as the second-youngest team in a NFC North division skewing toward the elderly. The Detroit Lions and Chicago Bears are the oldest and second-oldest teams in the league, respectively, and at a point where both of those clubs seem to be in flux -- the Lions are trying to rebound from a disappointing 2012 season, while the Bears have a new coach (Marc Trestman) and a quarterback in a contract year (Jay Cutler) -- the Vikings would seem to be in good standing. Only the Green Bay Packers, who have made a habit of remaining among the league's most youthful teams, are younger than the Vikings in the NFC. They rank fifth youngest overall.

But there's an interesting point to be made deeper in the numbers: The Vikings are actually older on both offense and defense than they are overall. They are 15th oldest on both offense and defense, with the league's seventh-youngest special-teams group pulling down their overall age. For a team that went wholeheartedly into draft-and-develop mode a couple years ago, though, the Vikings are hitting a crossroads.

They have four starters on defense this year -- Jared Allen, Kevin Williams, Brian Robison and Chad Greenway -- who are 30 or older. Three of those players are in contract years. General manager Rick Spielman ran counter to his recent strategy this offseason by giving a five-year contract to receiver Greg Jennings, who turns 30 next month. And the biggest thing to consider, as it relates to the Vikings' age, is this: Adrian Peterson is 28, right near the tipping point of where running backs start to decline. Time will tell if Peterson can avoid the kind of slowdown that has hit many running backs around age 29 or 30, but it's safe to say the Vikings won't have a better opportunity with him than they have right now.

The second point we'll make is one Seifert shared on Twitter this morning, while he was researching the Lions roster. He said only two of the Packers' 53 players -- Ryan Pickett and John Kuhn -- have played a snap for another team. The rest of the Packers roster is draft picks and undrafted free agents. Being as the Vikings are trying to follow a similar philosophy, I thought it'd be worth looking at where they stand. I counted 13 players -- Jared Allen, Joe Berger, Desmond Bishop, John Carlson, Matt Cassel, A.J. Jefferson, Jennings, Charlie Johnson, George Johnson, Troy Kropog, Marvin Mitchell, Andrew Sendejo and Jerome Simpson -- who have played for other teams.

Now, many of those players are backups, and the Vikings have been quite successful with their high draft picks under Spielman recently. But they're also not as far into a draft-and-develop phase as the Packers have been, and Spielman has showed he's been a little more willing to use free agency than Ted Thompson has (though certainly not as willing as he used to be). It will be interesting to see what the Vikings do after this season, when at least half of the players who came from other teams could be gone. Will they fill those jobs in-house, or will they look elsewhere? With a team constructed the way the Vikings currently are, that will be only one of a few things to sort out.