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The Minnesota Vikings had just finished an encouraging seven-win season under first-year head coach Mike Zimmer and rookie quarterback Teddy Bridgewater, but the self-congratulating was on hold.

There was no time for reflection inside the Vikings locker room. Focus had already shifted to 2015. An unshakable confidence had taken root in Minnesota's next opportunity to return to the postseason.

"I think we can be great," defensive end Everson Griffen said, via Chris Tomasson of the St. Paul Pioneer Press. "We got a lot of young players who stepped up and played big roles. We will be in the playoffs next year, definitely."

That was December. The calendar now reads May, but nothing about the events in between—including free agency and last week's NFL draft—should have Griffen wavering in his belief that the Vikings are a team that will break through as a postseason qualifier in 2015.

In fact, the Vikings represent the NFL's strongest dark horse to go from watching the playoffs in 2014 to participating in the postseason next season. Much still depends on Bridgewater's development as a second-year quarterback, but the talent around him is in place.

Minnesota isn't the only horse in the race. Several teams picking in the top half of the 2015 draft have taken notable steps forward this offseason.

The Tampa Bay Buccaneers and the Tennessee Titans both added franchise quarterbacks to rosters with talent on both sides of the ball.

The Jacksonville Jaguars now need nothing more than progression at quarterback to be competitive. The same could be said for the Oakland Raiders.

The Chicago Bears assembled an all-star coaching staff and quickly began restocking a newly aligned defense.

The Atlanta Falcons added missing pieces—including at pass-rusher and running back—around quarterback Matt Ryan.

The New York Giants should have a loaded offense ready to take on all comers in the NFC East.

The St. Louis Rams have a new quarterback, a stud rookie running back and one of the most talented defenses in football.

The Vikings, however, appear to have all the necessary pieces in place for a playoff run in 2015.

There is now a comfortable level of stability at head coach and quarterback. Zimmer leads a Minnesota defense packed with playmaking talent at every level, while Bridgewater controls an offense with big-name players at all the skill positions.

This offseason has only added to the foundation Minnesota laid in 2014.

The Vikings feel like they've made a significant upgrade at receiver, where an older, slower Greg Jennings was replaced with the blazing fast Mike Wallace. Jennings was a crafty veteran and a dependable pass-catcher for Norv Turner's new offense last season, but Wallace brings the kind of rare speed necessary for the vertical aspect of Turner's attack to finally come into place.

Maybe the most important move of Minnesota's offseason was a trade that didn't happen.

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Instead of shipping disgruntled running back Adrian Peterson to the highest bidder, the Vikings stood their ground and avoided the temptation to cave on Peterson's demands. He remains under contract in Minnesota. Barring some unforeseen series of events between now and September, the Vikings will bring back the best running back of the generation on fresh legs and with the motivation to put the disaster of 2014 behind him.

Add Wallace and Peterson to the return of tight end Kyle Rudolph from injury and the expected progression from Bridgewater, and the Vikings are likely to improve on the 20.3 points they scored per game last season.

So much still depends on the aforementioned development from Bridgewater, but Minnesota can feel good about his 103.0 passer rating and 72.1 completion percentage over the final five games of 2014. And recent history shows the majority of quarterbacks who start a significant number of games as rookies improve in Year 2.

If Bridgewater can handle his part of the equation, Zimmer will take care of the rest.

Last week's draft provided the defensive guru with two more toys. His defense needed another perimeter cornerback to pair with first-round pick Xavier Rhodes, so the Vikings selected Michigan State's Trae Waynes with the No. 11 overall pick. Minnesota also lacked a playmaking middle linebacker in 2014, so UCLA's Eric Kendricks was the choice at No. 45 in the second round.

In Waynes and Kendricks, the Vikings have two likely Week 1 starters for a defense now lacking a significant hole.

The defensive line is undeniably loaded, with Griffen, Sharrif Floyd, Linval Joseph, Brian Robison and Tom Johnson carrying most of the weight. Linebacker was once a problem area, but the additions of Kendricks and Anthony Barr—a seemingly ideal duo for today's NFL—have turned the position into a potential strength. The secondary has been completely remade, as the Vikings have used top picks (Rhodes, Waynes, Harrison Smith) and free-agent money (Captain Munnerlyn, Terence Newman) to give Zimmer all the ammo he needs at the back end.

The Vikings ended last season ranked 11th in points allowed. The expectation in 2015 will be a top-10 finish, and a ranking inside the top five really isn't out of the question. When scheme, coaching ability and talent come together like it has in Minnesota, anything is possible.

On special teams, all the major pieces return from a unit that finished 10th overall in The Dallas Morning News' annual and widely respected special teams rankings.

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If all goes to plan, there's little doubt the Vikings can improve by three wins and make the postseason in the NFC in 2015.

Still, nothing is guaranteed in the NFL, and the expectation of progression from young players can get prognosticators in trouble. The Vikings, as currently constructed, have accomplished very little. Zimmer is only 16 games into his head coaching career, and Bridgewater still hasn't started a full season.

But the promise of those opening acts and a few notable additions this offseason has Minnesota primed to surprise.

Just don't tell these Vikings they are simply dark horses. Expectations have been raised.

"If we don't make the playoffs next year, it's a bust," Munnerlyn told Tomasson. "There's so much young talent. We've got a rookie quarterback getting better each and every week, and next year he's not a rookie, so I definitely think it's playoffs or bust."

The last five months in Minnesota should have only reinforced the confidence.

Zach Kruse covers the NFL for Bleacher Report.

Follow @zachkruse2