The Minnesota Vikings have a lot of work to do, as much as they want to avoid the word "rebuilding." While they have skilled players at a number of positions, it's evident that the Vikings also have significant holes on their roster. They have depth at some key points, but will need to find players at defensive tackle, linebacker and safety.
Casual observers may note that the Vikings have had issues at wide receiver and cornerback, but offseason acquisitions have resolved some of the concerns at receiver and several returns from injury have helped their defensive back corps.
Bigger issues remain at the positions that were left poorly taken care of heading into the new season.
In the past decade the Vikings have had one of the best pairs of defensive tackles, comprised of Kevin and Pat Williams (no relation).
The Vikings' Tampa 2 system requires that the front four create pressure while the back seven manage coverage; it is not a very blitz-heavy system.
That means the team needs to put together a defensive line that constantly delivers sacks, hits and hurries.
Unfortunately, without a star nose tackle, the line can crumble. The departure of Pat Williams from that line has left a gaping hole in their defense that they haven't quite filled.
Despite an excellent edge rush, the Vikings were weak in the middle and couldn't force running backs to the WILL linebacker, as is their general strategy.
More importantly, they couldn't collapse the pocket to disrupt the pass.
The Vikings will be looking from more consistency from streaky nose tackles Letroy Guion and Fred Evans, but the consensus is that Guion is an average nose tackle at best and that Fred Evans is a liability.
The Vikings were so unimpressed with Guion heading into 2011 that they repeatedly started (but gave fewer snaps to) Remi Ayodele, who certainly underperformed.
Beyond that, Kevin Williams is aging and is expected to retire soon.
The importance of the front four in their defensive scheme will demand that the Vikings address what was once their greatest strength.
If Letroy Guion can improve his consistency, as has been his stated focus going into the season, he'll develop into an excellent nose tackle. Otherwise, next year could see two Williams-sized gaps.
The nose tackle is one of the two most important players in the Vikings' defensive philosophy, and the other is the middle linebacker.
Otherwise known as the MIKE, his responsibilities don't just include maintaining gap discipline in running plays, but also the agility and quickness to cover a deep third on passing downs.
Mike linebackers must have quick, sound footwork as well as excellent balance on the backpedal to make it to their assigned zone on time. Beyond that, they must also display all of the coverage abilities required of any zone player.
Aside from the passing game, the MIKE will also call all the defensive audibles and communicate adjustments to the line.
At this spot, the Vikings are starting an untested linebacker, Jasper Brinkley. Traditionally a "downhill" linebacker, Brinkley seems more suited as a run-stopping 3-4 ILB than a Tampa 2 MLB, and this difference causes a number of concerns for a Vikings team that allowed the league's highest opponent passer rating.
Behind him lies a field of potential, but no immediately obvious talent. The Vikings' best hope here is to move Erin Henderson, who has proved capable in coverage and has taken a number of snaps at MLB.
Will the Vikings be able to resolve these three positions?
This means having an acceptable backup at weak-side linebacker. Camp reports don't have any standout linebackers for this position, and the athletically capable Everson Griffen has a lot to learn before he is an adequate second-string WILL.
Seventh-round draft pick Audie Cole is a player in much the same mold as Jasper Brinkley and plays much better against the run than the pass.
The Vikings will need surprising development from Brinkley, or rely on the emergence of an unknown rookie. Either is generally a recipe for failure.
The other half of the equation of a pass defense that gave up the third-most yards per attempt in the league is the safety. With the MIKE, the safeties will generally cover the deep zone to prevent big plays. Both safeties need to be excellent tacklers and have a nose for the ball in the air.
The Vikings started four different safeties at different times over the course of the season, and the best of the bad bunch left the team to pursue religious obligations.
Mistral Raymond, a rookie, performed adequately, at best, and made a number of clear mistakes. Jamarca Sanford is regarded by Pro Football Focus as the worst-performing safety in 2011.
The other safety, Tyrell Johnson, was let go without a contract offer because of his poor play.
The Vikings moved back into the first round in order to draft Harrison Smith, generally regarded as the second-best safety in the draft. Smith hasn't been taking first-team reps in training camp yet, although many observers believe it's a matter of time.
Who starts alongside him is one of the bigger mysteries in camp, and there's no guarantee that the three biggest competitors—Raymond, Sanford and fifth-round pick Robert Blanton (converted from cornerback)—will produce a single player competent enough to play at a high level throughout the 2012 season.
Fans will expect the Vikings to fix their abysmal pass defense, and the safeties are a key aspect. Without serious improvement from one of the three other potential safeties, Harrison Smith's potential may not matter.
It is entirely possible that the Vikings produce solid players at each position. Some would even argue that the team is more likely than not to resolve these problems as the preseason moves forward. Vikings fans will wait with their fingers crossed, and hope that they can start the season with a bang.