Highest priority

New coach Mike Zimmer's toughest task, at least when it comes to overhauling the Vikings defense, is fixing a secondary that gave up a league-high 37 touchdown passes in 2013 while ranking 31st in pass defense. The defensive line and linebackers had a hand in that, but it starts with the secondary. The Vikings signed Captain Munnerlyn to play alongside promising second-year cornerback Xavier Rhodes. But the third corner spot — which is basically a starting position, too — is up for grabs, along with the safety spot next to Harrison Smith.

The heat is on

After the 2013 season ended, the Vikings prioritized re-signing 26-year-old defensive end Everson Griffen over fan favorite and sack specialist Jared Allen. Griffen ultimately was rewarded with a five-year, $42.5 million contract. Now he has to live up to it.

Griffen, who has 17½ career sacks in four seasons as a reserve, is projected to take over Allen's old right end spot, where he will be take on the NFL's top offensive tackles. The talent is there. Now there is an opportunity with the Vikings counting on him to punch up their revamped pass rush.

Breakout pick

Sure, there were growing pains for Rhodes in 2013. That is to be expected of most first-year cornerbacks. But the 2013 first-round pick made steady progress as a rookie and finished the season strong before he was sidelined in December because of an ankle injury. Under the close watch of Zimmer, Rhodes had a good spring, playing with a higher comfort level and, subsequently, more aggression.

To keep big and formidable NFC North receivers such as Calvin Johnson and Brandon Marshall in check, the Vikings will need Rhodes to keep on growing.

Rookie watch

Because of the presence of a first-round quarterback and also an NFL rule that kept linebacker Anthony Barr on campus, it's easy to forget Barr, not Teddy Bridgewater, was the Vikings' top pick. But they will give the ninth overall selection an opportunity to make his mark right away. While they stopped short of declaring Barr a starter, the expectation is he will at least have a significant role.

Zimmer still is figuring out the best way to use Barr — he could stand up on early downs and rush off the edge in passing situations — so he will be one to watch in Mankato.

Camp battle

Heading into training camp, the team's most unsettled position group — yes, even more unsettled than the defensive backs — is linebacker. We know that Chad Greenway will be one starter; we just don't know where. Barr is the favorite to start at strongside linebacker. And a group of youngsters will battle with veteran Jasper Brinkley, back north after a stint in the desert, for the other spot.

The middle linebacker position is wide open, and don't rule out Greenway moving inside. We could see countless combinations in camp until the top trio is chosen.

MATT VENSEL